11506581057 has 4 divisors (see below), whose sum is σ = 15342108080. Its totient is φ = 7671054036.

The previous prime is 11506581043. The next prime is 11506581067. The reversal of 11506581057 is 75018560511.

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: 75018560511 = 3 ⋅25006186837.

It is not a de Polignac number, because 11506581057 - 2⁴ = 11506581041 is a prime.

It is a super-2 number, since 2×11506581057² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11506581007) 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, 1917763507 + ... + 1917763512.

It is an arithmetic number, because the mean of its divisors is an integer number (3835527020).

Almost surely, 2^11506581057 is an apocalyptic number.

It is an amenable number.

11506581057 is a deficient number, since it is larger than the sum of its proper divisors (3835527023).

11506581057 is an equidigital number, since it uses as much as digits as its factorization.

11506581057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3835527022.

The product of its (nonzero) digits is 42000, while the sum is 39.

The spelling of 11506581057 in words is "eleven billion, five hundred six million, five hundred eighty-one thousand, fifty-seven".