311920813 has 2 divisors, whose sum is σ = 311920814. Its totient is φ = 311920812.

The previous prime is 311920801. The next prime is 311920823. The reversal of 311920813 is 318029113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 301821129 + 10099684 = 17373^2 + 3178^2 .

It is a cyclic number.

It is not a de Polignac number, because 311920813 - 2¹³ = 311912621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311920823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155960406 + 155960407.

It is an arithmetic number, because the mean of its divisors is an integer number (155960407).

Almost surely, 2^311920813 is an apocalyptic number.

It is an amenable number.

311920813 is a deficient number, since it is larger than the sum of its proper divisors (1).

311920813 is an equidigital number, since it uses as much as digits as its factorization.

311920813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 311920813 is about 17661.2800498718. The cubic root of 311920813 is about 678.1849034356.

Adding to 311920813 its reverse (318029113), we get a palindrome (629949926).

It can be divided in two parts, 3119 and 20813, that added together give a palindrome (23932).

The spelling of 311920813 in words is "three hundred eleven million, nine hundred twenty thousand, eight hundred thirteen".