21750553863 has 8 divisors (see below), whose sum is σ = 32223042800. Its totient is φ = 14500369224.

The previous prime is 21750553849. The next prime is 21750553907. The reversal of 21750553863 is 36835505712.

21750553863 is a `hidden beast` number, since 2 + 1 + 7 + 50 + 5 + 538 + 63 = 666.

It is not a de Polignac number, because 21750553863 - 2¹⁶ = 21750488327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21750553823) 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, 402788008 + ... + 402788061.

It is an arithmetic number, because the mean of its divisors is an integer number (4027880350).

Almost surely, 2^21750553863 is an apocalyptic number.

21750553863 is a deficient number, since it is larger than the sum of its proper divisors (10472488937).

21750553863 is an equidigital number, since it uses as much as digits as its factorization.

21750553863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805576078 (or 805576072 counting only the distinct ones).

The product of its (nonzero) digits is 756000, while the sum is 45.

The spelling of 21750553863 in words is "twenty-one billion, seven hundred fifty million, five hundred fifty-three thousand, eight hundred sixty-three".