21500111712 has 48 divisors (see below), whose sum is σ = 56619343872. Its totient is φ = 7143649920.

The previous prime is 21500111681. The next prime is 21500111719. The reversal of 21500111712 is 21711100512.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21500111719) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 330208 + ... + 389919.

It is an arithmetic number, because the mean of its divisors is an integer number (1179569664).

Almost surely, 2^21500111712 is an apocalyptic number.

It is an amenable number.

21500111712 is an abundant number, since it is smaller than the sum of its proper divisors (35119232160).

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

21500111712 is a wasteful number, since it uses less digits than its factorization.

21500111712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720451 (or 720443 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 21.

The spelling of 21500111712 in words is "twenty-one billion, five hundred million, one hundred eleven thousand, seven hundred twelve".