21893966 has 16 divisors (see below), whose sum is σ = 35376000. Its totient is φ = 10128888.

The previous prime is 21893939. The next prime is 21893987. The reversal of 21893966 is 66939812.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5066 + ... + 8333.

It is an arithmetic number, because the mean of its divisors is an integer number (2211000).

Almost surely, 2^21893966 is an apocalyptic number.

21893966 is a deficient number, since it is larger than the sum of its proper divisors (13482034).

21893966 is a wasteful number, since it uses less digits than its factorization.

21893966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13463.

The product of its digits is 139968, while the sum is 44.

The square root of 21893966 is about 4679.0988448632. The cubic root of 21893966 is about 279.7530390464.

The spelling of 21893966 in words is "twenty-one million, eight hundred ninety-three thousand, nine hundred sixty-six".