21660400120636 has 12 divisors (see below), whose sum is σ = 37905750981112. Its totient is φ = 10830185554608.

The previous prime is 21660400120591. The next prime is 21660400120657. The reversal of 21660400120636 is 63602100406612.

It is a junction number, because it is equal to n+sod(n) for n = 21660400120595 and 21660400120604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176446 + ... + 6584218.

Almost surely, 2^{21660400120636} is an apocalyptic number.

It is an amenable number.

21660400120636 is a deficient number, since it is larger than the sum of its proper divisors (16245350860476).

21660400120636 is a wasteful number, since it uses less digits than its factorization.

21660400120636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7252860 (or 7252858 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 37.

The spelling of 21660400120636 in words is "twenty-one trillion, six hundred sixty billion, four hundred million, one hundred twenty thousand, six hundred thirty-six".