21365665036 has 48 divisors (see below), whose sum is σ = 38103184000. Its totient is φ = 10481425920.

The previous prime is 21365665019. The next prime is 21365665043. The reversal of 21365665036 is 63056656312.

It is a junction number, because it is equal to n+sod(n) for n = 21365664983 and 21365665001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40851871 + ... + 40852393.

Almost surely, 2^21365665036 is an apocalyptic number.

It is an amenable number.

21365665036 is a deficient number, since it is larger than the sum of its proper divisors (16737518964).

21365665036 is a wasteful number, since it uses less digits than its factorization.

21365665036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1334 (or 1332 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 43.

The spelling of 21365665036 in words is "twenty-one billion, three hundred sixty-five million, six hundred sixty-five thousand, thirty-six".