21506662434536 has 16 divisors (see below), whose sum is σ = 40581839150340. Its totient is φ = 10684838661120.

The previous prime is 21506662434533. The next prime is 21506662434589. The reversal of 21506662434536 is 63543426660512.

It can be written as a sum of positive squares in 2 ways, for example, as 19015966132900 + 2490696301636 = 4360730^2 + 1578194^2 .

It is not an unprimeable number, because it can be changed into a prime (21506662434533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8561568185 + ... + 8561570696.

Almost surely, 2^{21506662434536} is an apocalyptic number.

It is an amenable number.

21506662434536 is a deficient number, since it is larger than the sum of its proper divisors (19075176715804).

21506662434536 is a wasteful number, since it uses less digits than its factorization.

21506662434536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17123139044 (or 17123139040 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 53.

The spelling of 21506662434536 in words is "twenty-one trillion, five hundred six billion, six hundred sixty-two million, four hundred thirty-four thousand, five hundred thirty-six".