21974398 has 8 divisors (see below), whose sum is σ = 33146280. Its totient is φ = 10925640.

The previous prime is 21974369. The next prime is 21974413. The reversal of 21974398 is 89347912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30333 + ... + 31048.

It is an arithmetic number, because the mean of its divisors is an integer number (4143285).

Almost surely, 2^21974398 is an apocalyptic number.

21974398 is a deficient number, since it is larger than the sum of its proper divisors (11171882).

21974398 is a wasteful number, since it uses less digits than its factorization.

21974398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61562.

The product of its digits is 108864, while the sum is 43.

The square root of 21974398 is about 4687.6857829850. The cubic root of 21974398 is about 280.0951972221.

The spelling of 21974398 in words is "twenty-one million, nine hundred seventy-four thousand, three hundred ninety-eight".