311840861 has 2 divisors, whose sum is σ = 311840862. Its totient is φ = 311840860.

The previous prime is 311840807. The next prime is 311840869. The reversal of 311840861 is 168048113.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213335236 + 98505625 = 14606^2 + 9925^2 .

It is a cyclic number.

It is not a de Polignac number, because 311840861 - 2¹⁸ = 311578717 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311840869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155920430 + 155920431.

It is an arithmetic number, because the mean of its divisors is an integer number (155920431).

Almost surely, 2^311840861 is an apocalyptic number.

It is an amenable number.

311840861 is a deficient number, since it is larger than the sum of its proper divisors (1).

311840861 is an equidigital number, since it uses as much as digits as its factorization.

311840861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 311840861 is about 17659.0164222133. The cubic root of 311840861 is about 678.1269540346.

Adding to 311840861 its reverse (168048113), we get a palindrome (479888974).

The spelling of 311840861 in words is "three hundred eleven million, eight hundred forty thousand, eight hundred sixty-one".