21922989 has 16 divisors (see below), whose sum is σ = 31967040. Its totient is φ = 13253760.

The previous prime is 21922969. The next prime is 21922993. The reversal of 21922989 is 98922912.

It is a happy number.

It is not a de Polignac number, because 21922989 - 2¹⁵ = 21890221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21922989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21922939) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22929 + ... + 23865.

It is an arithmetic number, because the mean of its divisors is an integer number (1997940).

Almost surely, 2^21922989 is an apocalyptic number.

It is an amenable number.

21922989 is a deficient number, since it is larger than the sum of its proper divisors (10044051).

21922989 is a wasteful number, since it uses less digits than its factorization.

21922989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1660.

The product of its digits is 46656, while the sum is 42.

The square root of 21922989 is about 4682.1991627866. The cubic root of 21922989 is about 279.8765995350.

The spelling of 21922989 in words is "twenty-one million, nine hundred twenty-two thousand, nine hundred eighty-nine".