21296918 has 4 divisors (see below), whose sum is σ = 31945380. Its totient is φ = 10648458.

The previous prime is 21296909. The next prime is 21296921. The reversal of 21296918 is 81969212.

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 pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5324228 + ... + 5324231.

It is an arithmetic number, because the mean of its divisors is an integer number (7986345).

Almost surely, 2^21296918 is an apocalyptic number.

21296918 is a deficient number, since it is larger than the sum of its proper divisors (10648462).

21296918 is a wasteful number, since it uses less digits than its factorization.

21296918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10648461.

The product of its digits is 15552, while the sum is 38.

The square root of 21296918 is about 4614.8583943605. The cubic root of 21296918 is about 277.1866137279.

The spelling of 21296918 in words is "twenty-one million, two hundred ninety-six thousand, nine hundred eighteen".