21187611852 has 48 divisors (see below), whose sum is σ = 54020289792. Its totient is φ = 6409990080.

The previous prime is 21187611847. The next prime is 21187611889. The reversal of 21187611852 is 25811678112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50008 + ... + 211839.

It is an arithmetic number, because the mean of its divisors is an integer number (1125422704).

Almost surely, 2^21187611852 is an apocalyptic number.

21187611852 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21187611852 is an abundant number, since it is smaller than the sum of its proper divisors (32832677940).

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

21187611852 is a wasteful number, since it uses less digits than its factorization.

21187611852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262478 (or 262476 counting only the distinct ones).

The product of its digits is 53760, while the sum is 42.

The spelling of 21187611852 in words is "twenty-one billion, one hundred eighty-seven million, six hundred eleven thousand, eight hundred fifty-two".