21922780 has 36 divisors (see below), whose sum is σ = 50609160. Its totient is φ = 7971040.

The previous prime is 21922763. The next prime is 21922781. The reversal of 21922780 is 8722912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21922781) 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 in 11 ways as a sum of consecutive naturals, for example, 2110 + ... + 6949.

It is an arithmetic number, because the mean of its divisors is an integer number (1405810).

Almost surely, 2^21922780 is an apocalyptic number.

21922780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21922780 is an abundant number, since it is smaller than the sum of its proper divisors (28686380).

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

21922780 is a wasteful number, since it uses less digits than its factorization.

21922780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9090 (or 9077 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 21922780 is about 4682.1768441613. The cubic root of 21922780 is about 279.8757101430.

The spelling of 21922780 in words is "twenty-one million, nine hundred twenty-two thousand, seven hundred eighty".