21980892 has 12 divisors (see below), whose sum is σ = 51288776. Its totient is φ = 7326960.

The previous prime is 21980857. The next prime is 21980897. The reversal of 21980892 is 29808912.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21980892² = 966319226231328, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21980892.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980897) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 915859 + ... + 915882.

Almost surely, 2^21980892 is an apocalyptic number.

It is an amenable number.

21980892 is an abundant number, since it is smaller than the sum of its proper divisors (29307884).

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

21980892 is a wasteful number, since it uses less digits than its factorization.

21980892 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1831748 (or 1831746 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 21980892 is about 4688.3783976979. The cubic root of 21980892 is about 280.1227862836.

The spelling of 21980892 in words is "twenty-one million, nine hundred eighty thousand, eight hundred ninety-two".