21797313 has 16 divisors (see below), whose sum is σ = 31099200. Its totient is φ = 13538880.

The previous prime is 21797297. The next prime is 21797327. The reversal of 21797313 is 31379712.

It is a happy number.

It is not a de Polignac number, because 21797313 - 2⁴ = 21797297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21797393) 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 15 ways as a sum of consecutive naturals, for example, 343 + ... + 6611.

It is an arithmetic number, because the mean of its divisors is an integer number (1943700).

Almost surely, 2^21797313 is an apocalyptic number.

It is an amenable number.

21797313 is a deficient number, since it is larger than the sum of its proper divisors (9301887).

21797313 is a wasteful number, since it uses less digits than its factorization.

21797313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6352.

The product of its digits is 7938, while the sum is 33.

The square root of 21797313 is about 4668.7592570189. The cubic root of 21797313 is about 279.3407662911.

The spelling of 21797313 in words is "twenty-one million, seven hundred ninety-seven thousand, three hundred thirteen".