20313391 has 6 divisors (see below), whose sum is σ = 23629920. Its totient is φ = 17411436.

The previous prime is 20313389. The next prime is 20313421. The reversal of 20313391 is 19331302.

20313391 is nontrivially palindromic in base 15.

It is not a de Polignac number, because 20313391 - 2¹ = 20313389 is a prime.

It is a super-3 number, since 3×20313391³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20313361) 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, 207231 + ... + 207328.

It is an arithmetic number, because the mean of its divisors is an integer number (3938320).

Almost surely, 2^20313391 is an apocalyptic number.

20313391 is a deficient number, since it is larger than the sum of its proper divisors (3316529).

20313391 is an equidigital number, since it uses as much as digits as its factorization.

20313391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414573 (or 414566 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 22.

The square root of 20313391 is about 4507.0379408210. The cubic root of 20313391 is about 272.8522101677.

Adding to 20313391 its reverse (19331302), we get a palindrome (39644693).

The spelling of 20313391 in words is "twenty million, three hundred thirteen thousand, three hundred ninety-one".