21935317 has 4 divisors (see below), whose sum is σ = 22080736. Its totient is φ = 21789900.

The previous prime is 21935311. The next prime is 21935357. The reversal of 21935317 is 71353912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21935317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21935311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72483 + ... + 72784.

It is an arithmetic number, because the mean of its divisors is an integer number (5520184).

Almost surely, 2^21935317 is an apocalyptic number.

It is an amenable number.

21935317 is a deficient number, since it is larger than the sum of its proper divisors (145419).

21935317 is a wasteful number, since it uses less digits than its factorization.

21935317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145418.

The product of its digits is 5670, while the sum is 31.

The square root of 21935317 is about 4683.5154531612. The cubic root of 21935317 is about 279.9290509013.

The spelling of 21935317 in words is "twenty-one million, nine hundred thirty-five thousand, three hundred seventeen".