21899684 has 6 divisors (see below), whose sum is σ = 38324454. Its totient is φ = 10949840.

The previous prime is 21899677. The next prime is 21899707. The reversal of 21899684 is 48699812.

It can be written as a sum of positive squares in only one way, i.e., 11075584 + 10824100 = 3328^2 + 3290^2 .

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, 2737457 + ... + 2737464.

It is an arithmetic number, because the mean of its divisors is an integer number (6387409).

Almost surely, 2^21899684 is an apocalyptic number.

It is an amenable number.

21899684 is a deficient number, since it is larger than the sum of its proper divisors (16424770).

21899684 is a wasteful number, since it uses less digits than its factorization.

21899684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5474925 (or 5474923 counting only the distinct ones).

The product of its digits is 248832, while the sum is 47.

The square root of 21899684 is about 4679.7098200636. The cubic root of 21899684 is about 279.7773910930. Note that the first 3 decimals are identical.

The spelling of 21899684 in words is "twenty-one million, eight hundred ninety-nine thousand, six hundred eighty-four".