1157261665 has 12 divisors (see below), whose sum is σ = 1615443156. Its totient is φ = 793550688.

The previous prime is 1157261653. The next prime is 1157261681. The reversal of 1157261665 is 5661627511.

It can be written as a sum of positive squares in 2 ways, for example, as 302342544 + 854919121 = 17388^2 + 29239^2 .

It is not a de Polignac number, because 1157261665 - 2¹¹ = 1157259617 is a prime.

It is a super-2 number, since 2×1157261665² = 2678509122557144450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2361514 + ... + 2362003.

It is an arithmetic number, because the mean of its divisors is an integer number (134620263).

Almost surely, 2^1157261665 is an apocalyptic number.

It is an amenable number.

1157261665 is a deficient number, since it is larger than the sum of its proper divisors (458181491).

1157261665 is an equidigital number, since it uses as much as digits as its factorization.

1157261665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4723536 (or 4723529 counting only the distinct ones).

The product of its digits is 75600, while the sum is 40.

The square root of 1157261665 is about 34018.5488373622. The cubic root of 1157261665 is about 1049.8901366534.

It can be divided in two parts, 11572 and 61665, that added together give a palindrome (73237).

The spelling of 1157261665 in words is "one billion, one hundred fifty-seven million, two hundred sixty-one thousand, six hundred sixty-five".