21995992 has 8 divisors (see below), whose sum is σ = 41242500. Its totient is φ = 10997992.

The previous prime is 21995951. The next prime is 21995993. The reversal of 21995992 is 29959912.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21995993) by changing a digit.

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 as a sum of consecutive naturals, namely, 1374742 + ... + 1374757.

Almost surely, 2^21995992 is an apocalyptic number.

It is an amenable number.

21995992 is a deficient number, since it is larger than the sum of its proper divisors (19246508).

21995992 is a wasteful number, since it uses less digits than its factorization.

21995992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2749505 (or 2749501 counting only the distinct ones).

The product of its digits is 131220, while the sum is 46.

The square root of 21995992 is about 4689.9884861266. The cubic root of 21995992 is about 280.1869160114.

The spelling of 21995992 in words is "twenty-one million, nine hundred ninety-five thousand, nine hundred ninety-two".