1156556665 has 16 divisors (see below), whose sum is σ = 1603100160. Its totient is φ = 791653120.

The previous prime is 1156556651. The next prime is 1156556669. The reversal of 1156556665 is 5666556511.

It is not a de Polignac number, because 1156556665 - 2¹³ = 1156548473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1156556669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 617545 + ... + 619414.

It is an arithmetic number, because the mean of its divisors is an integer number (100193760).

Almost surely, 2^1156556665 is an apocalyptic number.

It is an amenable number.

1156556665 is a deficient number, since it is larger than the sum of its proper divisors (446543495).

1156556665 is a wasteful number, since it uses less digits than its factorization.

1156556665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1236992.

The product of its digits is 810000, while the sum is 46.

The square root of 1156556665 is about 34008.1852647271. The cubic root of 1156556665 is about 1049.6768968065.

The spelling of 1156556665 in words is "one billion, one hundred fifty-six million, five hundred fifty-six thousand, six hundred sixty-five".