21316319 has 2 divisors, whose sum is σ = 21316320. Its totient is φ = 21316318.

The previous prime is 21316307. The next prime is 21316349. The reversal of 21316319 is 91361312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21316319 - 2⁸ = 21316063 is a prime.

It is a super-2 number, since 2×21316319² = 908770911419522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21316349) by changing a digit.

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, 10658159 + 10658160.

It is an arithmetic number, because the mean of its divisors is an integer number (10658160).

Almost surely, 2^21316319 is an apocalyptic number.

21316319 is a deficient number, since it is larger than the sum of its proper divisors (1).

21316319 is an equidigital number, since it uses as much as digits as its factorization.

21316319 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 972, while the sum is 26.

The square root of 21316319 is about 4616.9599305170. The cubic root of 21316319 is about 277.2707583810.

The spelling of 21316319 in words is "twenty-one million, three hundred sixteen thousand, three hundred nineteen".