21994980 has 48 divisors (see below), whose sum is σ = 70385280. Its totient is φ = 5027328.

The previous prime is 21994897. The next prime is 21994981. The reversal of 21994980 is 8949912.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21994981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25765 + ... + 26604.

It is an arithmetic number, because the mean of its divisors is an integer number (1466360).

Almost surely, 2^21994980 is an apocalyptic number.

21994980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21994980 is an abundant number, since it is smaller than the sum of its proper divisors (48390300).

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

21994980 is a wasteful number, since it uses less digits than its factorization.

21994980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52388 (or 52386 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 21994980 is about 4689.8805954949. The cubic root of 21994980 is about 280.1826189633.

The spelling of 21994980 in words is "twenty-one million, nine hundred ninety-four thousand, nine hundred eighty".