21919264 has 12 divisors (see below), whose sum is σ = 43153614. Its totient is φ = 10959616.

The previous prime is 21919259. The next prime is 21919277. The reversal of 21919264 is 46291912.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 1669264 = 4500^2 + 1292^2 .

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 as a sum of consecutive naturals, namely, 342457 + ... + 342520.

Almost surely, 2^21919264 is an apocalyptic number.

It is an amenable number.

21919264 is a deficient number, since it is larger than the sum of its proper divisors (21234350).

21919264 is an equidigital number, since it uses as much as digits as its factorization.

21919264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684987 (or 684979 counting only the distinct ones).

The product of its digits is 7776, while the sum is 34.

The square root of 21919264 is about 4681.8013627235. The cubic root of 21919264 is about 279.8607470831.

The spelling of 21919264 in words is "twenty-one million, nine hundred nineteen thousand, two hundred sixty-four".