21653639366 has 16 divisors (see below), whose sum is σ = 32675256240. Its totient is φ = 10762053120.

The previous prime is 21653639341. The next prime is 21653639401. The reversal of 21653639366 is 66393635612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 222590 + ... + 304718.

It is an arithmetic number, because the mean of its divisors is an integer number (2042203515).

Almost surely, 2^21653639366 is an apocalyptic number.

21653639366 is a deficient number, since it is larger than the sum of its proper divisors (11021616874).

21653639366 is a wasteful number, since it uses less digits than its factorization.

21653639366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82919.

The product of its digits is 3149280, while the sum is 50.

The spelling of 21653639366 in words is "twenty-one billion, six hundred fifty-three million, six hundred thirty-nine thousand, three hundred sixty-six".