21874051 has 4 divisors (see below), whose sum is σ = 22232704. Its totient is φ = 21515400.

The previous prime is 21874049. The next prime is 21874063. The reversal of 21874051 is 15047812.

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

It is a cyclic number.

It is not a de Polignac number, because 21874051 - 2¹ = 21874049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21874451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 179235 + ... + 179356.

It is an arithmetic number, because the mean of its divisors is an integer number (5558176).

Almost surely, 2^21874051 is an apocalyptic number.

21874051 is a deficient number, since it is larger than the sum of its proper divisors (358653).

21874051 is an equidigital number, since it uses as much as digits as its factorization.

21874051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358652.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 21874051 is about 4676.9702799996. The cubic root of 21874051 is about 279.6681911350.

It can be divided in two parts, 218740 and 51, that added together give a triangular number (218791 = T₆₆₁).

The spelling of 21874051 in words is "twenty-one million, eight hundred seventy-four thousand, fifty-one".