21698964 has 54 divisors (see below), whose sum is σ = 63810474. Its totient is φ = 6199200.

The previous prime is 21698933. The next prime is 21698993. The reversal of 21698964 is 46989612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17288964 + 4410000 = 4158^2 + 2100^2 .

It is a congruent number.

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 in 17 ways as a sum of consecutive naturals, for example, 4387 + ... + 7914.

Almost surely, 2^21698964 is an apocalyptic number.

It is an amenable number.

21698964 is an abundant number, since it is smaller than the sum of its proper divisors (42111510).

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

21698964 is a wasteful number, since it uses less digits than its factorization.

21698964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12325 (or 12313 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 21698964 is about 4658.2146794668. The cubic root of 21698964 is about 278.9200063572.

The spelling of 21698964 in words is "twenty-one million, six hundred ninety-eight thousand, nine hundred sixty-four".