21534645384 has 96 divisors (see below), whose sum is σ = 66684072000. Its totient is φ = 6150059136.

The previous prime is 21534645383. The next prime is 21534645427. The reversal of 21534645384 is 48354643512.

21534645384 is a `hidden beast` number, since 2 + 1 + 53 + 4 + 64 + 538 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (21534645383) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1332102 + ... + 1348170.

It is an arithmetic number, because the mean of its divisors is an integer number (694625750).

Almost surely, 2^21534645384 is an apocalyptic number.

21534645384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21534645384 is an abundant number, since it is smaller than the sum of its proper divisors (45149426616).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21534645384 is a wasteful number, since it uses less digits than its factorization.

21534645384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18747 (or 18740 counting only the distinct ones).

The product of its digits is 1382400, while the sum is 45.

The spelling of 21534645384 in words is "twenty-one billion, five hundred thirty-four million, six hundred forty-five thousand, three hundred eighty-four".