21654384807 has 24 divisors (see below), whose sum is σ = 32284333440. Its totient is φ = 12803742400.

The previous prime is 21654384803. The next prime is 21654384821. The reversal of 21654384807 is 70848345612.

It is not a de Polignac number, because 21654384807 - 2² = 21654384803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21654384803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139707 + ... + 250652.

It is an arithmetic number, because the mean of its divisors is an integer number (1345180560).

Almost surely, 2^21654384807 is an apocalyptic number.

21654384807 is a deficient number, since it is larger than the sum of its proper divisors (10629948633).

21654384807 is a wasteful number, since it uses less digits than its factorization.

21654384807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390455 (or 390414 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 48.

The spelling of 21654384807 in words is "twenty-one billion, six hundred fifty-four million, three hundred eighty-four thousand, eight hundred seven".