21879982 has 16 divisors (see below), whose sum is σ = 34650000. Its totient is φ = 10333440.

The previous prime is 21879961. The next prime is 21880009. The reversal of 21879982 is 28997812.

It is a super-2 number, since 2×21879982² = 957467224640648, 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 7 ways as a sum of consecutive naturals, for example, 16894 + ... + 18142.

It is an arithmetic number, because the mean of its divisors is an integer number (2165625).

Almost surely, 2^21879982 is an apocalyptic number.

21879982 is a deficient number, since it is larger than the sum of its proper divisors (12770018).

21879982 is a wasteful number, since it uses less digits than its factorization.

21879982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1731.

The product of its digits is 145152, while the sum is 46.

The square root of 21879982 is about 4677.6043013491. The cubic root of 21879982 is about 279.6934655594.

It can be divided in two parts, 218 and 79982, that added together give a triangular number (80200 = T₄₀₀).

The spelling of 21879982 in words is "twenty-one million, eight hundred seventy-nine thousand, nine hundred eighty-two".