123551422520 has 128 divisors (see below), whose sum is σ = 291998908800. Its totient is φ = 46984863744.

The previous prime is 123551422487. The next prime is 123551422567. The reversal of 123551422520 is 25224155321.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 101022629 + ... + 101023851.

It is an arithmetic number, because the mean of its divisors is an integer number (2281241475).

Almost surely, 2^123551422520 is an apocalyptic number.

123551422520 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 123551422520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145999454400).

123551422520 is an abundant number, since it is smaller than the sum of its proper divisors (168447486280).

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

123551422520 is a wasteful number, since it uses less digits than its factorization.

123551422520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2529 (or 2525 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 32.

Adding to 123551422520 its reverse (25224155321), we get a palindrome (148775577841).

The spelling of 123551422520 in words is "one hundred twenty-three billion, five hundred fifty-one million, four hundred twenty-two thousand, five hundred twenty".