21633388605 has 32 divisors (see below), whose sum is σ = 38466489600. Its totient is φ = 11535667776.

The previous prime is 21633388603. The next prime is 21633388613. The reversal of 21633388605 is 50688333612.

21633388605 is a `hidden beast` number, since 2 + 1 + 6 + 3 + 3 + 38 + 8 + 605 = 666.

It is not a de Polignac number, because 21633388605 - 2¹ = 21633388603 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633388603) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 944347 + ... + 966983.

It is an arithmetic number, because the mean of its divisors is an integer number (1202077800).

Almost surely, 2^21633388605 is an apocalyptic number.

It is an amenable number.

21633388605 is a deficient number, since it is larger than the sum of its proper divisors (16833100995).

21633388605 is a wasteful number, since it uses less digits than its factorization.

21633388605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29730 (or 29724 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 21633388605 in words is "twenty-one billion, six hundred thirty-three million, three hundred eighty-eight thousand, six hundred five".