20513313 has 6 divisors (see below), whose sum is σ = 29630354. Its totient is φ = 13675536.

The previous prime is 20513303. The next prime is 20513327. The reversal of 20513313 is 31331502.

It can be written as a sum of positive squares in only one way, i.e., 10419984 + 10093329 = 3228^2 + 3177^2 .

It is not a de Polignac number, because 20513313 - 2⁸ = 20513057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20513303) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1139620 + ... + 1139637.

Almost surely, 2^20513313 is an apocalyptic number.

It is an amenable number.

20513313 is a deficient number, since it is larger than the sum of its proper divisors (9117041).

20513313 is a wasteful number, since it uses less digits than its factorization.

20513313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2279263 (or 2279260 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 18.

The square root of 20513313 is about 4529.1625053645. The cubic root of 20513313 is about 273.7444159742.

Adding to 20513313 its reverse (31331502), we get a palindrome (51844815).

The spelling of 20513313 in words is "twenty million, five hundred thirteen thousand, three hundred thirteen".