21977316 has 36 divisors (see below), whose sum is σ = 56102592. Its totient is φ = 7253424.

The previous prime is 21977299. The next prime is 21977317. The reversal of 21977316 is 61377912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21977317) 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, 745 + ... + 6671.

Almost surely, 2^21977316 is an apocalyptic number.

It is an amenable number.

21977316 is an abundant number, since it is smaller than the sum of its proper divisors (34125276).

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

21977316 is a wasteful number, since it uses less digits than its factorization.

21977316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6040 (or 6035 counting only the distinct ones).

The product of its digits is 15876, while the sum is 36.

The square root of 21977316 is about 4687.9970136509. The cubic root of 21977316 is about 280.1075947041.

The spelling of 21977316 in words is "twenty-one million, nine hundred seventy-seven thousand, three hundred sixteen".