21913874 has 4 divisors (see below), whose sum is σ = 32870814. Its totient is φ = 10956936.

The previous prime is 21913861. The next prime is 21913933. The reversal of 21913874 is 47831912.

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., 16120225 + 5793649 = 4015^2 + 2407^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5478467 + ... + 5478470.

Almost surely, 2^21913874 is an apocalyptic number.

21913874 is a deficient number, since it is larger than the sum of its proper divisors (10956940).

21913874 is a wasteful number, since it uses less digits than its factorization.

21913874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10956939.

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

The square root of 21913874 is about 4681.2256941959. The cubic root of 21913874 is about 279.8378057245.

The spelling of 21913874 in words is "twenty-one million, nine hundred thirteen thousand, eight hundred seventy-four".