2311251561 has 24 divisors (see below), whose sum is σ = 3517119840. Its totient is φ = 1458518400.

The previous prime is 2311251559. The next prime is 2311251563. The reversal of 2311251561 is 1651521132.

It is an interprime number because it is at equal distance from previous prime (2311251559) and next prime (2311251563).

It is not a de Polignac number, because 2311251561 - 2¹ = 2311251559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2311251563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 227766 + ... + 237696.

It is an arithmetic number, because the mean of its divisors is an integer number (146546660).

Almost surely, 2^2311251561 is an apocalyptic number.

It is an amenable number.

2311251561 is a deficient number, since it is larger than the sum of its proper divisors (1205868279).

2311251561 is a wasteful number, since it uses less digits than its factorization.

2311251561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11317 (or 11314 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 2311251561 is about 48075.4777511363. The cubic root of 2311251561 is about 1322.1551038566.

Adding to 2311251561 its reverse (1651521132), we get a palindrome (3962772693).

The spelling of 2311251561 in words is "two billion, three hundred eleven million, two hundred fifty-one thousand, five hundred sixty-one".