21879628 has 12 divisors (see below), whose sum is σ = 39104352. Its totient is φ = 10706960.

The previous prime is 21879593. The next prime is 21879631. The reversal of 21879628 is 82697812.

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, 58003 + ... + 58378.

It is an arithmetic number, because the mean of its divisors is an integer number (3258696).

Almost surely, 2^21879628 is an apocalyptic number.

It is an amenable number.

21879628 is a deficient number, since it is larger than the sum of its proper divisors (17224724).

21879628 is a wasteful number, since it uses less digits than its factorization.

21879628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116432 (or 116430 counting only the distinct ones).

The product of its digits is 96768, while the sum is 43.

The square root of 21879628 is about 4677.5664613130. The cubic root of 21879628 is about 279.6919571484.

The spelling of 21879628 in words is "twenty-one million, eight hundred seventy-nine thousand, six hundred twenty-eight".