21170313 has 12 divisors (see below), whose sum is σ = 32189040. Its totient is φ = 13370616.

The previous prime is 21170297. The next prime is 21170323. The reversal of 21170313 is 31307112.

It is not a de Polignac number, because 21170313 - 2⁴ = 21170297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21170323) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61731 + ... + 62072.

It is an arithmetic number, because the mean of its divisors is an integer number (2682420).

Almost surely, 2^21170313 is an apocalyptic number.

It is an amenable number.

21170313 is a deficient number, since it is larger than the sum of its proper divisors (11018727).

21170313 is a wasteful number, since it uses less digits than its factorization.

21170313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123828 (or 123825 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 21170313 is about 4601.1208417080. The cubic root of 21170313 is about 276.6362526848.

Adding to 21170313 its reverse (31307112), we get a palindrome (52477425).

The spelling of 21170313 in words is "twenty-one million, one hundred seventy thousand, three hundred thirteen".