20315213 has 8 divisors (see below), whose sum is σ = 20870136. Its totient is φ = 19763200.

The previous prime is 20315203. The next prime is 20315219. The reversal of 20315213 is 31251302.

It can be written as a sum of positive squares in 4 ways, for example, as 128164 + 20187049 = 358^2 + 4493^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20315213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20315191 and 20315200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20315219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25895 + ... + 26667.

It is an arithmetic number, because the mean of its divisors is an integer number (2608767).

Almost surely, 2^20315213 is an apocalyptic number.

It is an amenable number.

20315213 is a deficient number, since it is larger than the sum of its proper divisors (554923).

20315213 is an equidigital number, since it uses as much as digits as its factorization.

20315213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1455.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 20315213 is about 4507.2400646072. The cubic root of 20315213 is about 272.8603677071.

Multiplying 20315213 by its sum of digits (17), we get a triangular number (345358621 = T₂₆₂₈₁).

Adding to 20315213 its reverse (31251302), we get a palindrome (51566515).

The spelling of 20315213 in words is "twenty million, three hundred fifteen thousand, two hundred thirteen".