21992398 has 8 divisors (see below), whose sum is σ = 33010560. Its totient is φ = 10988880.

The previous prime is 21992357. The next prime is 21992401. The reversal of 21992398 is 89329912.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 1618 + ... + 6826.

It is an arithmetic number, because the mean of its divisors is an integer number (4126320).

Almost surely, 2^21992398 is an apocalyptic number.

21992398 is a deficient number, since it is larger than the sum of its proper divisors (11018162).

21992398 is a wasteful number, since it uses less digits than its factorization.

21992398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7322.

The product of its digits is 69984, while the sum is 43.

The square root of 21992398 is about 4689.6053138830. The cubic root of 21992398 is about 280.1716549489.

The spelling of 21992398 in words is "twenty-one million, nine hundred ninety-two thousand, three hundred ninety-eight".