12155761577 has 4 divisors (see below), whose sum is σ = 12174152196. Its totient is φ = 12137370960.

The previous prime is 12155761573. The next prime is 12155761591. The reversal of 12155761577 is 77516755121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77516755121 = 13 ⋅5962827317.

It can be written as a sum of positive squares in 2 ways, for example, as 7845707776 + 4310053801 = 88576^2 + 65651^2 .

It is a cyclic number.

It is not a de Polignac number, because 12155761577 - 2² = 12155761573 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12155761573) 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, 9194318 + ... + 9195639.

It is an arithmetic number, because the mean of its divisors is an integer number (3043538049).

Almost surely, 2^12155761577 is an apocalyptic number.

It is an amenable number.

12155761577 is a deficient number, since it is larger than the sum of its proper divisors (18390619).

12155761577 is an equidigital number, since it uses as much as digits as its factorization.

12155761577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18390618.

The product of its digits is 514500, while the sum is 47.

The spelling of 12155761577 in words is "twelve billion, one hundred fifty-five million, seven hundred sixty-one thousand, five hundred seventy-seven".