21304718 has 4 divisors (see below), whose sum is σ = 31957080. Its totient is φ = 10652358.

The previous prime is 21304709. The next prime is 21304721. The reversal of 21304718 is 81740312.

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 (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5326178 + ... + 5326181.

It is an arithmetic number, because the mean of its divisors is an integer number (7989270).

Almost surely, 2^21304718 is an apocalyptic number.

21304718 is a deficient number, since it is larger than the sum of its proper divisors (10652362).

21304718 is a wasteful number, since it uses less digits than its factorization.

21304718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10652361.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21304718 is about 4615.7034133488. The cubic root of 21304718 is about 277.2204494796.

It can be divided in two parts, 21304 and 718, that added together give a palindrome (22022).

The spelling of 21304718 in words is "twenty-one million, three hundred four thousand, seven hundred eighteen".