21995768 has 16 divisors (see below), whose sum is σ = 43413000. Its totient is φ = 10418976.

The previous prime is 21995759. The next prime is 21995791. The reversal of 21995768 is 86759912.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 72203 + ... + 72506.

Almost surely, 2^21995768 is an apocalyptic number.

It is an amenable number.

21995768 is a deficient number, since it is larger than the sum of its proper divisors (21417232).

21995768 is a wasteful number, since it uses less digits than its factorization.

21995768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144734 (or 144730 counting only the distinct ones).

The product of its digits is 272160, while the sum is 47.

The square root of 21995768 is about 4689.9646054102. The cubic root of 21995768 is about 280.1859648975.

The spelling of 21995768 in words is "twenty-one million, nine hundred ninety-five thousand, seven hundred sixty-eight".