21964578540 has 48 divisors (see below), whose sum is σ = 63621542880. Its totient is φ = 5655247360.

The previous prime is 21964578539. The next prime is 21964578557. The reversal of 21964578540 is 4587546912.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6309921 + ... + 6313400.

It is an arithmetic number, because the mean of its divisors is an integer number (1325448810).

Almost surely, 2^21964578540 is an apocalyptic number.

21964578540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21964578540 is an abundant number, since it is smaller than the sum of its proper divisors (41656964340).

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

21964578540 is a wasteful number, since it uses less digits than its factorization.

21964578540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12623362 (or 12623360 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 51.

The spelling of 21964578540 in words is "twenty-one billion, nine hundred sixty-four million, five hundred seventy-eight thousand, five hundred forty".