21239232012 has 36 divisors (see below), whose sum is σ = 53737099416. Its totient is φ = 7073277120.

The previous prime is 21239232011. The next prime is 21239232017. The reversal of 21239232012 is 21023293212.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21239232012² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21239232011) 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 11 ways as a sum of consecutive naturals, for example, 229414 + ... + 308397.

It is an arithmetic number, because the mean of its divisors is an integer number (1492697206).

Almost surely, 2^21239232012 is an apocalyptic number.

It is an amenable number.

21239232012 is an abundant number, since it is smaller than the sum of its proper divisors (32497867404).

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

21239232012 is a wasteful number, since it uses less digits than its factorization.

21239232012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538918 (or 538913 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The spelling of 21239232012 in words is "twenty-one billion, two hundred thirty-nine million, two hundred thirty-two thousand, twelve".