21919868 has 12 divisors (see below), whose sum is σ = 40616352. Its totient is φ = 10315200.

The previous prime is 21919847. The next prime is 21919903. The reversal of 21919868 is 86891912.

It is a super-2 number, since 2×21919868² = 960961226274848, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161108 + ... + 161243.

It is an arithmetic number, because the mean of its divisors is an integer number (3384696).

Almost surely, 2^21919868 is an apocalyptic number.

It is an amenable number.

21919868 is a deficient number, since it is larger than the sum of its proper divisors (18696484).

21919868 is a wasteful number, since it uses less digits than its factorization.

21919868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322372 (or 322370 counting only the distinct ones).

The product of its digits is 62208, while the sum is 44.

The square root of 21919868 is about 4681.8658673653. The cubic root of 21919868 is about 279.8633176429.

The spelling of 21919868 in words is "twenty-one million, nine hundred nineteen thousand, eight hundred sixty-eight".