1156556161 has 8 divisors (see below), whose sum is σ = 1161958824. Its totient is φ = 1151162880.

The previous prime is 1156556117. The next prime is 1156556171. The reversal of 1156556161 is 1616556511.

It can be written as a sum of positive squares in 4 ways, for example, as 678915136 + 477641025 = 26056^2 + 21855^2 .

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 1156556161 - 2¹⁷ = 1156425089 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1156556161.

It is not an unprimeable number, because it can be changed into a prime (1156556171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 378801 + ... + 381841.

It is an arithmetic number, because the mean of its divisors is an integer number (145244853).

Almost surely, 2^1156556161 is an apocalyptic number.

It is an amenable number.

1156556161 is a deficient number, since it is larger than the sum of its proper divisors (5402663).

1156556161 is a wasteful number, since it uses less digits than its factorization.

1156556161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4691.

The product of its digits is 27000, while the sum is 37.

The square root of 1156556161 is about 34008.1778547455. The cubic root of 1156556161 is about 1049.6767443317.

The spelling of 1156556161 in words is "one billion, one hundred fifty-six million, five hundred fifty-six thousand, one hundred sixty-one".