21715946 has 16 divisors (see below), whose sum is σ = 38094144. Its totient is φ = 9090144.

The previous prime is 21715931. The next prime is 21715951. The reversal of 21715946 is 64951712.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon 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, 17435 + ... + 18638.

It is an arithmetic number, because the mean of its divisors is an integer number (2380884).

Almost surely, 2^21715946 is an apocalyptic number.

21715946 is a deficient number, since it is larger than the sum of its proper divisors (16378198).

21715946 is a wasteful number, since it uses less digits than its factorization.

21715946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36125.

The product of its digits is 15120, while the sum is 35.

The square root of 21715946 is about 4660.0371243156. The cubic root of 21715946 is about 278.9927499904.

The spelling of 21715946 in words is "twenty-one million, seven hundred fifteen thousand, nine hundred forty-six".