2131156765 has 8 divisors (see below), whose sum is σ = 2605641048. Its totient is φ = 1672756800.

The previous prime is 2131156739. The next prime is 2131156787. The reversal of 2131156765 is 5676511312.

It can be written as a sum of positive squares in 4 ways, for example, as 352763524 + 1778393241 = 18782^2 + 42171^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2131156765 - 2⁹ = 2131156253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4020786 + ... + 4021315.

It is an arithmetic number, because the mean of its divisors is an integer number (325705131).

Almost surely, 2^2131156765 is an apocalyptic number.

It is an amenable number.

2131156765 is a deficient number, since it is larger than the sum of its proper divisors (474484283).

2131156765 is an equidigital number, since it uses as much as digits as its factorization.

2131156765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8042159.

The product of its digits is 37800, while the sum is 37.

The square root of 2131156765 is about 46164.4534788402. The cubic root of 2131156765 is about 1286.8812276602.

The spelling of 2131156765 in words is "two billion, one hundred thirty-one million, one hundred fifty-six thousand, seven hundred sixty-five".