11909556257 has 4 divisors (see below), whose sum is σ = 12087310896. Its totient is φ = 11731801620.

The previous prime is 11909556251. The next prime is 11909556287. The reversal of 11909556257 is 75265590911.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75265590911 = 7 ⋅10752227273.

It is a cyclic number.

It is not a de Polignac number, because 11909556257 - 2¹⁶ = 11909490721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11909556251) 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, 88877219 + ... + 88877352.

It is an arithmetic number, because the mean of its divisors is an integer number (3021827724).

Almost surely, 2^11909556257 is an apocalyptic number.

It is an amenable number.

11909556257 is a deficient number, since it is larger than the sum of its proper divisors (177754639).

11909556257 is an equidigital number, since it uses as much as digits as its factorization.

11909556257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177754638.

The product of its (nonzero) digits is 850500, while the sum is 50.

The spelling of 11909556257 in words is "eleven billion, nine hundred nine million, five hundred fifty-six thousand, two hundred fifty-seven".