21874394 has 4 divisors (see below), whose sum is σ = 32811594. Its totient is φ = 10937196.

The previous prime is 21874367. The next prime is 21874397. The reversal of 21874394 is 49347812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21855625 + 18769 = 4675^2 + 137^2 .

It is a super-2 number, since 2×21874394² = 956978225734472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21874397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5468597 + ... + 5468600.

Almost surely, 2^21874394 is an apocalyptic number.

21874394 is a deficient number, since it is larger than the sum of its proper divisors (10937200).

21874394 is a wasteful number, since it uses less digits than its factorization.

21874394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10937199.

The product of its digits is 48384, while the sum is 38.

The square root of 21874394 is about 4677.0069488937. The cubic root of 21874394 is about 279.6696529232.

The spelling of 21874394 in words is "twenty-one million, eight hundred seventy-four thousand, three hundred ninety-four".