123256289520 has 960 divisors, whose sum is σ = 550371024000. Its totient is φ = 25100845056.

The previous prime is 123256289407. The next prime is 123256289521. The reversal of 123256289520 is 25982652321.

123256289520 is a `hidden beast` number, since 1 + 2 + 3 + 2 + 562 + 89 + 5 + 2 + 0 = 666.

It is a super-2 number, since 2×123256289520² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123256289521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 39900136 + ... + 39903224.

It is an arithmetic number, because the mean of its divisors is an integer number (573303150).

Almost surely, 2^123256289520 is an apocalyptic number.

123256289520 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 123256289520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275185512000).

123256289520 is an abundant number, since it is smaller than the sum of its proper divisors (427114734480).

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

123256289520 is a wasteful number, since it uses less digits than its factorization.

123256289520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3167 (or 3148 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 123256289520 in words is "one hundred twenty-three billion, two hundred fifty-six million, two hundred eighty-nine thousand, five hundred twenty".