21874018 has 4 divisors (see below), whose sum is σ = 32811030. Its totient is φ = 10937008.

The previous prime is 21874009. The next prime is 21874037. The reversal of 21874018 is 81047812.

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., 18122049 + 3751969 = 4257^2 + 1937^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5468503 + ... + 5468506.

Almost surely, 2^21874018 is an apocalyptic number.

21874018 is a deficient number, since it is larger than the sum of its proper divisors (10937012).

21874018 is a wasteful number, since it uses less digits than its factorization.

21874018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10937011.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 21874018 is about 4676.9667520734. The cubic root of 21874018 is about 279.6680504957.

The spelling of 21874018 in words is "twenty-one million, eight hundred seventy-four thousand, eighteen".