311522136521 has 4 divisors (see below), whose sum is σ = 312463291344. Its totient is φ = 310580981700.

The previous prime is 311522136481. The next prime is 311522136547. The reversal of 311522136521 is 125631225113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-311522136521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (311522136551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 470576915 + ... + 470577576.

It is an arithmetic number, because the mean of its divisors is an integer number (78115822836).

Almost surely, 2^311522136521 is an apocalyptic number.

It is an amenable number.

311522136521 is a deficient number, since it is larger than the sum of its proper divisors (941154823).

311522136521 is an equidigital number, since it uses as much as digits as its factorization.

311522136521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941154822.

The product of its digits is 10800, while the sum is 32.

The spelling of 311522136521 in words is "three hundred eleven billion, five hundred twenty-two million, one hundred thirty-six thousand, five hundred twenty-one".