31232120520 has 128 divisors (see below), whose sum is σ = 99346953600. Its totient is φ = 7827664896.

The previous prime is 31232120519. The next prime is 31232120527. The reversal of 31232120520 is 2502123213.

It is not an unprimeable number, because it can be changed into a prime (31232120527) 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, 1497202 + ... + 1517918.

It is an arithmetic number, because the mean of its divisors is an integer number (776148075).

Almost surely, 2^31232120520 is an apocalyptic number.

31232120520 is a gapful number since it is divisible by the number (30) 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 31232120520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49673476800).

31232120520 is an abundant number, since it is smaller than the sum of its proper divisors (68114833080).

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

31232120520 is a wasteful number, since it uses less digits than its factorization.

31232120520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21487 (or 21483 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

Adding to 31232120520 its reverse (2502123213), we get a palindrome (33734243733).

The spelling of 31232120520 in words is "thirty-one billion, two hundred thirty-two million, one hundred twenty thousand, five hundred twenty".