1265655761 has 8 divisors (see below), whose sum is σ = 1283368320. Its totient is φ = 1247985648.

The previous prime is 1265655757. The next prime is 1265655779. The reversal of 1265655761 is 1675565621.

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

It is a cyclic number.

It is not a de Polignac number, because 1265655761 - 2² = 1265655757 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1265655161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51995 + ... + 72351.

It is an arithmetic number, because the mean of its divisors is an integer number (160421040).

Almost surely, 2^1265655761 is an apocalyptic number.

It is an amenable number.

1265655761 is a deficient number, since it is larger than the sum of its proper divisors (17712559).

1265655761 is an equidigital number, since it uses as much as digits as its factorization.

1265655761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21223.

The product of its digits is 378000, while the sum is 44.

The square root of 1265655761 is about 35576.0560068145. The cubic root of 1265655761 is about 1081.6959411241.

The spelling of 1265655761 in words is "one billion, two hundred sixty-five million, six hundred fifty-five thousand, seven hundred sixty-one".