21326600655 has 12 divisors (see below), whose sum is σ = 36966107880. Its totient is φ = 11374186992.

The previous prime is 21326600639. The next prime is 21326600693. The reversal of 21326600655 is 55600662312.

It is a happy number.

21326600655 is a `hidden beast` number, since 21 + 3 + 26 + 600 + 6 + 5 + 5 = 666.

It is not a de Polignac number, because 21326600655 - 2⁴ = 21326600639 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 236962185 + ... + 236962274.

It is an arithmetic number, because the mean of its divisors is an integer number (3080508990).

Almost surely, 2^21326600655 is an apocalyptic number.

21326600655 is a deficient number, since it is larger than the sum of its proper divisors (15639507225).

21326600655 is a wasteful number, since it uses less digits than its factorization.

21326600655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473924470 (or 473924467 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 21326600655 in words is "twenty-one billion, three hundred twenty-six million, six hundred thousand, six hundred fifty-five".