123661352520 has 96 divisors (see below), whose sum is σ = 401943667320. Its totient is φ = 32972728320.

The previous prime is 123661352513. The next prime is 123661352533. The reversal of 123661352520 is 25253166321.

123661352520 is a `hidden beast` number, since 1 + 2 + 36 + 613 + 5 + 2 + 5 + 2 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 72198615204 + 51462737316 = 268698^2 + 226854^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 5432202 + ... + 5454918.

Almost surely, 2^123661352520 is an apocalyptic number.

123661352520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

123661352520 is an abundant number, since it is smaller than the sum of its proper divisors (278282314800).

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

123661352520 is a wasteful number, since it uses less digits than its factorization.

123661352520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37855 (or 37848 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 123661352520 in words is "one hundred twenty-three billion, six hundred sixty-one million, three hundred fifty-two thousand, five hundred twenty".