21661016106432 has 56 divisors (see below), whose sum is σ = 57599435728000. Its totient is φ = 7184055580416.

The previous prime is 21661016106407. The next prime is 21661016106437. The reversal of 21661016106432 is 23460161016612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21661016106437) 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, 283423582 + ... + 283499997.

Almost surely, 2^{21661016106432} is an apocalyptic number.

It is an amenable number.

21661016106432 is an abundant number, since it is smaller than the sum of its proper divisors (35938419621568).

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

21661016106432 is a wasteful number, since it uses less digits than its factorization.

21661016106432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566923793 (or 566923783 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The spelling of 21661016106432 in words is "twenty-one trillion, six hundred sixty-one billion, sixteen million, one hundred six thousand, four hundred thirty-two".