21977160 has 64 divisors (see below), whose sum is σ = 66242880. Its totient is φ = 5832960.

The previous prime is 21977159. The next prime is 21977177. The reversal of 21977160 is 6177912.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44515 + ... + 45005.

It is an arithmetic number, because the mean of its divisors is an integer number (1035045).

Almost surely, 2^21977160 is an apocalyptic number.

21977160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21977160 is an abundant number, since it is smaller than the sum of its proper divisors (44265720).

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

21977160 is a wasteful number, since it uses less digits than its factorization.

21977160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878 (or 874 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 21977160 is about 4687.9803753855. The cubic root of 21977160 is about 280.1069319466.

The spelling of 21977160 in words is "twenty-one million, nine hundred seventy-seven thousand, one hundred sixty".