123345213405520 has 160 divisors (see below), whose sum is σ = 314165470471200. Its totient is φ = 44827758624768.

The previous prime is 123345213405517. The next prime is 123345213405523. The reversal of 123345213405520 is 25504312543321.

It is an interprime number because it is at equal distance from previous prime (123345213405517) and next prime (123345213405523).

It can be written as a sum of positive squares in 16 ways, for example, as 70795530624064 + 52549682781456 = 8414008^2 + 7249116^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123345213405523) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 261527676 + ... + 261998884.

It is an arithmetic number, because the mean of its divisors is an integer number (1963534190445).

Almost surely, 2^{123345213405520} is an apocalyptic number.

123345213405520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 123345213405520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157082735235600).

123345213405520 is an abundant number, since it is smaller than the sum of its proper divisors (190820257065680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

123345213405520 is a wasteful number, since it uses less digits than its factorization.

123345213405520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477905 (or 477899 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 40.

Adding to 123345213405520 its reverse (25504312543321), we get a palindrome (148849525948841).

The spelling of 123345213405520 in words is "one hundred twenty-three trillion, three hundred forty-five billion, two hundred thirteen million, four hundred five thousand, five hundred twenty".