311312561 has 16 divisors (see below), whose sum is σ = 373912704. Its totient is φ = 253580544.

The previous prime is 311312531. The next prime is 311312563. The reversal of 311312561 is 165213113.

It is not a de Polignac number, because 311312561 - 2¹⁰ = 311311537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (311312563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2840 + ... + 25113.

It is an arithmetic number, because the mean of its divisors is an integer number (23369544).

Almost surely, 2^311312561 is an apocalyptic number.

It is an amenable number.

311312561 is a deficient number, since it is larger than the sum of its proper divisors (62600143).

311312561 is a wasteful number, since it uses less digits than its factorization.

311312561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28040.

The product of its digits is 540, while the sum is 23.

The square root of 311312561 is about 17644.0517172219. The cubic root of 311312561 is about 677.7437917494.

Adding to 311312561 its reverse (165213113), we get a palindrome (476525674).

The spelling of 311312561 in words is "three hundred eleven million, three hundred twelve thousand, five hundred sixty-one".