21965994 has 12 divisors (see below), whose sum is σ = 47593026. Its totient is φ = 7321992.

The previous prime is 21965987. The next prime is 21966019. The reversal of 21965994 is 49956912.

It can be written as a sum of positive squares in only one way, i.e., 12510369 + 9455625 = 3537^2 + 3075^2 .

It is a Curzon 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 5 ways as a sum of consecutive naturals, for example, 610149 + ... + 610184.

Almost surely, 2^21965994 is an apocalyptic number.

21965994 is an abundant number, since it is smaller than the sum of its proper divisors (25627032).

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

21965994 is a wasteful number, since it uses less digits than its factorization.

21965994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220341 (or 1220338 counting only the distinct ones).

The product of its digits is 174960, while the sum is 45.

The square root of 21965994 is about 4686.7893061242. The cubic root of 21965994 is about 280.0594856608.

The spelling of 21965994 in words is "twenty-one million, nine hundred sixty-five thousand, nine hundred ninety-four".