21719313 has 64 divisors (see below), whose sum is σ = 41533440. Its totient is φ = 10886400.

The previous prime is 21719309. The next prime is 21719339. The reversal of 21719313 is 31391712.

It is not a de Polignac number, because 21719313 - 2² = 21719309 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21719303) by changing a digit.

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 in 63 ways as a sum of consecutive naturals, for example, 64281 + ... + 64617.

It is an arithmetic number, because the mean of its divisors is an integer number (648960).

Almost surely, 2^21719313 is an apocalyptic number.

It is an amenable number.

21719313 is a deficient number, since it is larger than the sum of its proper divisors (19814127).

21719313 is a wasteful number, since it uses less digits than its factorization.

21719313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395 (or 389 counting only the distinct ones).

The product of its digits is 1134, while the sum is 27.

The square root of 21719313 is about 4660.3983735299. The cubic root of 21719313 is about 279.0071682746.

The spelling of 21719313 in words is "twenty-one million, seven hundred nineteen thousand, three hundred thirteen".