21810982 has 16 divisors (see below), whose sum is σ = 33767712. Its totient is φ = 10558080.

The previous prime is 21810947. The next prime is 21810991. The reversal of 21810982 is 28901812.

It is a happy number.

It is a congruent 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, 17223 + ... + 18445.

It is an arithmetic number, because the mean of its divisors is an integer number (2110482).

Almost surely, 2^21810982 is an apocalyptic number.

21810982 is a deficient number, since it is larger than the sum of its proper divisors (11956730).

21810982 is a wasteful number, since it uses less digits than its factorization.

21810982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1503.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 21810982 is about 4670.2229068857. Note that the first 3 decimals coincide. The cubic root of 21810982 is about 279.3991452155.

The spelling of 21810982 in words is "twenty-one million, eight hundred ten thousand, nine hundred eighty-two".