21989364 has 24 divisors (see below), whose sum is σ = 54327168. Its totient is φ = 6898560.

The previous prime is 21989291. The next prime is 21989369. The reversal of 21989364 is 46398912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21989369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53692 + ... + 54099.

It is an arithmetic number, because the mean of its divisors is an integer number (2263632).

Almost surely, 2^21989364 is an apocalyptic number.

It is an amenable number.

21989364 is an abundant number, since it is smaller than the sum of its proper divisors (32337804).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21989364 is a wasteful number, since it uses less digits than its factorization.

21989364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107815 (or 107813 counting only the distinct ones).

The product of its digits is 93312, while the sum is 42.

The square root of 21989364 is about 4689.2818213454. The cubic root of 21989364 is about 280.1587704984.

The spelling of 21989364 in words is "twenty-one million, nine hundred eighty-nine thousand, three hundred sixty-four".