11571881 has 4 divisors (see below), whose sum is σ = 11854164. Its totient is φ = 11289600.

The previous prime is 11571851. The next prime is 11571913. The reversal of 11571881 is 18817511.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 409600 + 11162281 = 640^2 + 3341^2 .

It is a cyclic number.

It is not a de Polignac number, because 11571881 - 2¹⁰ = 11570857 is a prime.

It is a super-2 number, since 2×11571881² = 267816859756322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11571811) 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, 141080 + ... + 141161.

It is an arithmetic number, because the mean of its divisors is an integer number (2963541).

Almost surely, 2^11571881 is an apocalyptic number.

It is an amenable number.

11571881 is a deficient number, since it is larger than the sum of its proper divisors (282283).

11571881 is an equidigital number, since it uses as much as digits as its factorization.

11571881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282282.

The product of its digits is 2240, while the sum is 32.

The square root of 11571881 is about 3401.7467571823. The cubic root of 11571881 is about 226.1871801417.

The spelling of 11571881 in words is "eleven million, five hundred seventy-one thousand, eight hundred eighty-one".