11551513261 has 6 divisors (see below), whose sum is σ = 12075590030. Its totient is φ = 11049273048.

The previous prime is 11551513241. The next prime is 11551513301. The reversal of 11551513261 is 16231515511.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 10855556100 + 695957161 = 104190^2 + 26381^2 .

It is not a de Polignac number, because 11551513261 - 2⁷ = 11551513133 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 (11551513241) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10917726 + ... + 10918783.

Almost surely, 2^11551513261 is an apocalyptic number.

It is an amenable number.

11551513261 is a deficient number, since it is larger than the sum of its proper divisors (524076769).

11551513261 is an equidigital number, since it uses as much as digits as its factorization.

11551513261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21836555 (or 21836532 counting only the distinct ones).

The product of its digits is 4500, while the sum is 31.

The spelling of 11551513261 in words is "eleven billion, five hundred fifty-one million, five hundred thirteen thousand, two hundred sixty-one".