21994963728 has 40 divisors (see below), whose sum is σ = 56915256000. Its totient is φ = 7319405184.

The previous prime is 21994963721. The next prime is 21994963751. The reversal of 21994963728 is 82736949912.

It is not an unprimeable number, because it can be changed into a prime (21994963721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353743 + ... + 411246.

It is an arithmetic number, because the mean of its divisors is an integer number (1422881400).

Almost surely, 2^21994963728 is an apocalyptic number.

It is an amenable number.

21994963728 is an abundant number, since it is smaller than the sum of its proper divisors (34920292272).

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

21994963728 is a wasteful number, since it uses less digits than its factorization.

21994963728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765599 (or 765593 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 60.

The spelling of 21994963728 in words is "twenty-one billion, nine hundred ninety-four million, nine hundred sixty-three thousand, seven hundred twenty-eight".