21897122 has 32 divisors (see below), whose sum is σ = 37884672. Its totient is φ = 9402624.

The previous prime is 21897097. The next prime is 21897133. The reversal of 21897122 is 22179812.

It is a happy 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 15 ways as a sum of consecutive naturals, for example, 47063 + ... + 47525.

It is an arithmetic number, because the mean of its divisors is an integer number (1183896).

Almost surely, 2^21897122 is an apocalyptic number.

21897122 is a deficient number, since it is larger than the sum of its proper divisors (15987550).

21897122 is a wasteful number, since it uses less digits than its factorization.

21897122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602.

The product of its digits is 4032, while the sum is 32.

The square root of 21897122 is about 4679.4360771358. The cubic root of 21897122 is about 279.7664804693.

The spelling of 21897122 in words is "twenty-one million, eight hundred ninety-seven thousand, one hundred twenty-two".