21974318 has 4 divisors (see below), whose sum is σ = 32961480. Its totient is φ = 10987158.

The previous prime is 21974299. The next prime is 21974321. The reversal of 21974318 is 81347912.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5493578 + ... + 5493581.

It is an arithmetic number, because the mean of its divisors is an integer number (8240370).

Almost surely, 2^21974318 is an apocalyptic number.

21974318 is a deficient number, since it is larger than the sum of its proper divisors (10987162).

21974318 is a wasteful number, since it uses less digits than its factorization.

21974318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10987161.

The product of its digits is 12096, while the sum is 35.

The square root of 21974318 is about 4687.6772499821. The cubic root of 21974318 is about 280.0948573168.

The spelling of 21974318 in words is "twenty-one million, nine hundred seventy-four thousand, three hundred eighteen".