21655628464 has 10 divisors (see below), whose sum is σ = 41957780180. Its totient is φ = 10827814224.

The previous prime is 21655628443. The next prime is 21655628473. The reversal of 21655628464 is 46482655612.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 676738374 + ... + 676738405.

It is an arithmetic number, because the mean of its divisors is an integer number (4195778018).

Almost surely, 2^21655628464 is an apocalyptic number.

It is an amenable number.

21655628464 is a deficient number, since it is larger than the sum of its proper divisors (20302151716).

21655628464 is a wasteful number, since it uses less digits than its factorization.

21655628464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1353476787 (or 1353476781 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 49.

The spelling of 21655628464 in words is "twenty-one billion, six hundred fifty-five million, six hundred twenty-eight thousand, four hundred sixty-four".