21919946 has 16 divisors (see below), whose sum is σ = 33377280. Its totient is φ = 10795680.

The previous prime is 21919927. The next prime is 21919951. The reversal of 21919946 is 64991912.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53390 + ... + 53798.

It is an arithmetic number, because the mean of its divisors is an integer number (2086080).

Almost surely, 2^21919946 is an apocalyptic number.

21919946 is a deficient number, since it is larger than the sum of its proper divisors (11457334).

21919946 is a wasteful number, since it uses less digits than its factorization.

21919946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 749.

The product of its digits is 34992, while the sum is 41.

The square root of 21919946 is about 4681.8741973701. The cubic root of 21919946 is about 279.8636495992.

The spelling of 21919946 in words is "twenty-one million, nine hundred nineteen thousand, nine hundred forty-six".