21195317 has 32 divisors (see below), whose sum is σ = 27216000. Its totient is φ = 16208640.

The previous prime is 21195313. The next prime is 21195323. The reversal of 21195317 is 71359112.

It is a cyclic number.

It is not a de Polignac number, because 21195317 - 2² = 21195313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21195317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21195313) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 78659 + ... + 78927.

It is an arithmetic number, because the mean of its divisors is an integer number (850500).

Almost surely, 2^21195317 is an apocalyptic number.

It is an amenable number.

21195317 is a deficient number, since it is larger than the sum of its proper divisors (6020683).

21195317 is a wasteful number, since it uses less digits than its factorization.

21195317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341.

The product of its digits is 1890, while the sum is 29.

The square root of 21195317 is about 4603.8372038985. The cubic root of 21195317 is about 276.7451204099.

It can be divided in two parts, 21195 and 317, that added together give a palindrome (21512).

The spelling of 21195317 in words is "twenty-one million, one hundred ninety-five thousand, three hundred seventeen".