21873764 has 24 divisors (see below), whose sum is σ = 44216928. Its totient is φ = 9357440.

The previous prime is 21873739. The next prime is 21873773. The reversal of 21873764 is 46737812.

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 7 ways as a sum of consecutive naturals, for example, 13874 + ... + 15369.

It is an arithmetic number, because the mean of its divisors is an integer number (1842372).

Almost surely, 2^21873764 is an apocalyptic number.

It is an amenable number.

21873764 is an abundant number, since it is smaller than the sum of its proper divisors (22343164).

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

21873764 is a wasteful number, since it uses less digits than its factorization.

21873764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29275 (or 29273 counting only the distinct ones).

The product of its digits is 56448, while the sum is 38.

The square root of 21873764 is about 4676.9395976429. The cubic root of 21873764 is about 279.6669679943. Note that the first 3 decimals are identical.

The spelling of 21873764 in words is "twenty-one million, eight hundred seventy-three thousand, seven hundred sixty-four".