21420602664 has 16 divisors (see below), whose sum is σ = 53551506720. Its totient is φ = 7140200880.

The previous prime is 21420602663. The next prime is 21420602677. The reversal of 21420602664 is 46620602412.

It is not an unprimeable number, because it can be changed into a prime (21420602663) 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 3 ways as a sum of consecutive naturals, for example, 446262532 + ... + 446262579.

It is an arithmetic number, because the mean of its divisors is an integer number (3346969170).

Almost surely, 2^21420602664 is an apocalyptic number.

21420602664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21420602664 is an abundant number, since it is smaller than the sum of its proper divisors (32130904056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21420602664 is a wasteful number, since it uses less digits than its factorization.

21420602664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 892525120 (or 892525116 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The spelling of 21420602664 in words is "twenty-one billion, four hundred twenty million, six hundred two thousand, six hundred sixty-four".