123401520 has 120 divisors (see below), whose sum is σ = 452127312. Its totient is φ = 29913600.

The previous prime is 123401507. The next prime is 123401533. The reversal of 123401520 is 25104321.

It is an interprime number because it is at equal distance from previous prime (123401507) and next prime (123401533).

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 123401493 and 123401502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 130 + ... + 15710.

Almost surely, 2^123401520 is an apocalyptic number.

123401520 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 123401520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (226063656).

123401520 is an abundant number, since it is smaller than the sum of its proper divisors (328725792).

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

123401520 is a wasteful number, since it uses less digits than its factorization.

123401520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15611 (or 15602 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 123401520 is about 11108.6236771258. The cubic root of 123401520 is about 497.8595432990.

Adding to 123401520 its reverse (25104321), we get a palindrome (148505841).

The spelling of 123401520 in words is "one hundred twenty-three million, four hundred one thousand, five hundred twenty".