21757364 has 6 divisors (see below), whose sum is σ = 38075394. Its totient is φ = 10878680.

The previous prime is 21757361. The next prime is 21757387. The reversal of 21757364 is 46375712.

It can be written as a sum of positive squares in only one way, i.e., 16467364 + 5290000 = 4058^2 + 2300^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21757361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2719667 + ... + 2719674.

It is an arithmetic number, because the mean of its divisors is an integer number (6345899).

Almost surely, 2^21757364 is an apocalyptic number.

It is an amenable number.

21757364 is a deficient number, since it is larger than the sum of its proper divisors (16318030).

21757364 is a wasteful number, since it uses less digits than its factorization.

21757364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5439345 (or 5439343 counting only the distinct ones).

The product of its digits is 35280, while the sum is 35.

The square root of 21757364 is about 4664.4789633999. The cubic root of 21757364 is about 279.1700081083.

The spelling of 21757364 in words is "twenty-one million, seven hundred fifty-seven thousand, three hundred sixty-four".