1156561061 has 4 divisors (see below), whose sum is σ = 1156674624. Its totient is φ = 1156447500.

The previous prime is 1156561019. The next prime is 1156561073. The reversal of 1156561061 is 1601656511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1156561061 - 2⁶ = 1156560997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1156563061) 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 3 ways as a sum of consecutive naturals, for example, 39815 + ... + 62436.

It is an arithmetic number, because the mean of its divisors is an integer number (289168656).

Almost surely, 2^1156561061 is an apocalyptic number.

It is an amenable number.

1156561061 is a deficient number, since it is larger than the sum of its proper divisors (113563).

1156561061 is a wasteful number, since it uses less digits than its factorization.

1156561061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113562.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 1156561061 is about 34008.2498961649. The cubic root of 1156561061 is about 1049.6782267237.

The spelling of 1156561061 in words is "one billion, one hundred fifty-six million, five hundred sixty-one thousand, sixty-one".