21977344 has 27 divisors (see below), whose sum is σ = 44019073. Its totient is φ = 10951168.

The previous prime is 21977339. The next prime is 21977363. The reversal of 21977344 is 44377912.

The square root of 21977344 is 4688.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 20793600 + 1183744 = 4560^2 + 1088^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 74862 + ... + 75154.

Almost surely, 2^21977344 is an apocalyptic number.

21977344 is the 4688-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21977344

21977344 is an abundant number, since it is smaller than the sum of its proper divisors (22041729).

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

21977344 is an frugal number, since it uses more digits than its factorization.

21977344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602 (or 295 counting only the distinct ones).

The product of its digits is 42336, while the sum is 37.

The cubic root of 21977344 is about 280.1077136602.

The spelling of 21977344 in words is "twenty-one million, nine hundred seventy-seven thousand, three hundred forty-four".