21507604020736 has 40 divisors (see below), whose sum is σ = 42977667282264. Its totient is φ = 10752684349440.

The previous prime is 21507604020649. The next prime is 21507604020737. The reversal of 21507604020736 is 63702040670512.

It is a junction number, because it is equal to n+sod(n) for n = 21507604020692 and 21507604020701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21507604020737) 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, 2759106 + ... + 7115326.

Almost surely, 2^{21507604020736} is an apocalyptic number.

It is an amenable number.

21507604020736 is a deficient number, since it is larger than the sum of its proper divisors (21470063261528).

21507604020736 is an frugal number, since it uses more digits than its factorization.

21507604020736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4365882 (or 4365866 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 43.

The spelling of 21507604020736 in words is "twenty-one trillion, five hundred seven billion, six hundred four million, twenty thousand, seven hundred thirty-six".