21506021652 has 96 divisors (see below), whose sum is σ = 51600697344. Its totient is φ = 6969139200.

The previous prime is 21506021627. The next prime is 21506021687. The reversal of 21506021652 is 25612060512.

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, 26983318 + ... + 26984114.

It is an arithmetic number, because the mean of its divisors is an integer number (537507264).

Almost surely, 2^21506021652 is an apocalyptic number.

It is an amenable number.

21506021652 is an abundant number, since it is smaller than the sum of its proper divisors (30094675692).

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

21506021652 is a wasteful number, since it uses less digits than its factorization.

21506021652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249 (or 1247 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21506021652 in words is "twenty-one billion, five hundred six million, twenty-one thousand, six hundred fifty-two".