11556332261 has 4 divisors (see below), whose sum is σ = 11559189024. Its totient is φ = 11553475500.

The previous prime is 11556332191. The next prime is 11556332279. The reversal of 11556332261 is 16223365511.

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 11556332261 - 2¹⁸ = 11556070117 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 (11556332561) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1422305 + ... + 1430406.

It is an arithmetic number, because the mean of its divisors is an integer number (2889797256).

Almost surely, 2^11556332261 is an apocalyptic number.

It is an amenable number.

11556332261 is a deficient number, since it is larger than the sum of its proper divisors (2856763).

11556332261 is an equidigital number, since it uses as much as digits as its factorization.

11556332261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2856762.

The product of its digits is 32400, while the sum is 35.

Adding to 11556332261 its reverse (16223365511), we get a palindrome (27779697772).

The spelling of 11556332261 in words is "eleven billion, five hundred fifty-six million, three hundred thirty-two thousand, two hundred sixty-one".