21036253563 has 12 divisors (see below), whose sum is σ = 32723061280. Its totient is φ = 12945386736.

The previous prime is 21036253559. The next prime is 21036253573. The reversal of 21036253563 is 36535263012.

21036253563 is a `hidden beast` number, since 2 + 1 + 0 + 3 + 62 + 535 + 63 = 666.

It is not a de Polignac number, because 21036253563 - 2² = 21036253559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21036253573) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 89898403 + ... + 89898636.

Almost surely, 2^21036253563 is an apocalyptic number.

21036253563 is a deficient number, since it is larger than the sum of its proper divisors (11686807717).

21036253563 is a wasteful number, since it uses less digits than its factorization.

21036253563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179797058 (or 179797055 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 36.

The spelling of 21036253563 in words is "twenty-one billion, thirty-six million, two hundred fifty-three thousand, five hundred sixty-three".