21654642004 has 48 divisors (see below), whose sum is σ = 39004072128. Its totient is φ = 10516036608.

The previous prime is 21654641929. The next prime is 21654642011. The reversal of 21654642004 is 40024645612.

It is a super-2 number, since 2×21654642004² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7615407 + ... + 7618249.

It is an arithmetic number, because the mean of its divisors is an integer number (812584836).

Almost surely, 2^21654642004 is an apocalyptic number.

It is an amenable number.

21654642004 is a deficient number, since it is larger than the sum of its proper divisors (17349430124).

21654642004 is a wasteful number, since it uses less digits than its factorization.

21654642004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3304 (or 3302 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 34.

The spelling of 21654642004 in words is "twenty-one billion, six hundred fifty-four million, six hundred forty-two thousand, four".