20993964 has 12 divisors (see below), whose sum is σ = 48985944. Its totient is φ = 6997984.

The previous prime is 20993953. The next prime is 20993971. The reversal of 20993964 is 46939902.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 874737 + ... + 874760.

It is an arithmetic number, because the mean of its divisors is an integer number (4082162).

Almost surely, 2^20993964 is an apocalyptic number.

It is an amenable number.

20993964 is an abundant number, since it is smaller than the sum of its proper divisors (27991980).

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

20993964 is a wasteful number, since it uses less digits than its factorization.

20993964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1749504 (or 1749502 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 42.

The square root of 20993964 is about 4581.9170660325. The cubic root of 20993964 is about 275.8659819840.

The spelling of 20993964 in words is "twenty million, nine hundred ninety-three thousand, nine hundred sixty-four".