21162874 has 4 divisors (see below), whose sum is σ = 31744314. Its totient is φ = 10581436.

The previous prime is 21162871. The next prime is 21162877. The reversal of 21162874 is 47826112.

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

It is an interprime number because it is at equal distance from previous prime (21162871) and next prime (21162877).

It can be written as a sum of positive squares in only one way, i.e., 17766225 + 3396649 = 4215^2 + 1843^2 .

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 not an unprimeable number, because it can be changed into a prime (21162871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5290717 + ... + 5290720.

Almost surely, 2^21162874 is an apocalyptic number.

21162874 is a deficient number, since it is larger than the sum of its proper divisors (10581440).

21162874 is a wasteful number, since it uses less digits than its factorization.

21162874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10581439.

The product of its digits is 5376, while the sum is 31.

The square root of 21162874 is about 4600.3123806976. The cubic root of 21162874 is about 276.6038466426.

Adding to 21162874 its reverse (47826112), we get a palindrome (68988986).

The spelling of 21162874 in words is "twenty-one million, one hundred sixty-two thousand, eight hundred seventy-four".