21977360 has 40 divisors (see below), whose sum is σ = 52864920. Its totient is φ = 8486912.

The previous prime is 21977339. The next prime is 21977363. The reversal of 21977360 is 6377912.

It can be written as a sum of positive squares in 4 ways, for example, as 7929856 + 14047504 = 2816^2 + 3748^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 21977360.

It is not an unprimeable number, because it can be changed into a prime (21977363) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2417 + ... + 7056.

It is an arithmetic number, because the mean of its divisors is an integer number (1321623).

Almost surely, 2^21977360 is an apocalyptic number.

21977360 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21977360 is an abundant number, since it is smaller than the sum of its proper divisors (30887560).

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

21977360 is a wasteful number, since it uses less digits than its factorization.

21977360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9515 (or 9509 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 35.

The square root of 21977360 is about 4688.0017064843. The cubic root of 21977360 is about 280.1077816351.

The spelling of 21977360 in words is "twenty-one million, nine hundred seventy-seven thousand, three hundred sixty".