11611371557 has 4 divisors (see below), whose sum is σ = 11680900896. Its totient is φ = 11541842220.

The previous prime is 11611371539. The next prime is 11611371601. The reversal of 11611371557 is 75517311611.

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: 75517311611 = 7 ⋅10788187373.

It is a cyclic number.

It is not a de Polignac number, because 11611371557 - 2⁸ = 11611371301 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 11611371557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11611371757) 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, 34764419 + ... + 34764752.

It is an arithmetic number, because the mean of its divisors is an integer number (2920225224).

Almost surely, 2^11611371557 is an apocalyptic number.

It is an amenable number.

11611371557 is a deficient number, since it is larger than the sum of its proper divisors (69529339).

11611371557 is an equidigital number, since it uses as much as digits as its factorization.

11611371557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69529338.

The product of its digits is 22050, while the sum is 38.

The spelling of 11611371557 in words is "eleven billion, six hundred eleven million, three hundred seventy-one thousand, five hundred fifty-seven".