21064542633 has 6 divisors (see below), whose sum is σ = 30426561594. Its totient is φ = 14043028416.

The previous prime is 21064542623. The next prime is 21064542739. The reversal of 21064542633 is 33624546012.

21064542633 is a `hidden beast` number, since 2 + 1 + 0 + 645 + 4 + 2 + 6 + 3 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 19686054249 + 1378488384 = 140307^2 + 37128^2 .

It is not a de Polignac number, because 21064542633 - 2³² = 16769575337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21064542623) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 1170252360 + ... + 1170252377.

It is an arithmetic number, because the mean of its divisors is an integer number (5071093599).

Almost surely, 2^21064542633 is an apocalyptic number.

It is an amenable number.

21064542633 is a deficient number, since it is larger than the sum of its proper divisors (9362018961).

21064542633 is a wasteful number, since it uses less digits than its factorization.

21064542633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2340504743 (or 2340504740 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The spelling of 21064542633 in words is "twenty-one billion, sixty-four million, five hundred forty-two thousand, six hundred thirty-three".