311205315961 has 4 divisors (see below), whose sum is σ = 312817778932. Its totient is φ = 309592852992.

The previous prime is 311205315959. The next prime is 311205316013. The reversal of 311205315961 is 169513502113.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 169513502113 = 5003 ⋅33882371.

It can be written as a sum of positive squares in 2 ways, for example, as 213263858025 + 97941457936 = 461805^2 + 312956^2 .

It is a cyclic number.

It is not a de Polignac number, because 311205315961 - 2¹ = 311205315959 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 311205315961.

It is not an unprimeable number, because it can be changed into a prime (311205315931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 806231196 + ... + 806231581.

It is an arithmetic number, because the mean of its divisors is an integer number (78204444733).

Almost surely, 2^311205315961 is an apocalyptic number.

It is an amenable number.

311205315961 is a deficient number, since it is larger than the sum of its proper divisors (1612462971).

311205315961 is a wasteful number, since it uses less digits than its factorization.

311205315961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1612462970.

The product of its (nonzero) digits is 24300, while the sum is 37.

The spelling of 311205315961 in words is "three hundred eleven billion, two hundred five million, three hundred fifteen thousand, nine hundred sixty-one".