21953280664 has 48 divisors (see below), whose sum is σ = 49427426880. Its totient is φ = 9105042240.

The previous prime is 21953280653. The next prime is 21953280683. The reversal of 21953280664 is 46608235912.

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, 891127 + ... + 915430.

It is an arithmetic number, because the mean of its divisors is an integer number (1029738060).

Almost surely, 2^21953280664 is an apocalyptic number.

It is an amenable number.

21953280664 is an abundant number, since it is smaller than the sum of its proper divisors (27474146216).

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

21953280664 is a wasteful number, since it uses less digits than its factorization.

21953280664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1806608 (or 1806597 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 21953280664 in words is "twenty-one billion, nine hundred fifty-three million, two hundred eighty thousand, six hundred sixty-four".