11857249881 has 63 divisors (see below), whose sum is σ = 18440371341. Its totient is φ = 7620627744.

The previous prime is 11857249841. The next prime is 11857249907. The reversal of 11857249881 is 18894275811.

The square root of 11857249881 is 108891.

It is a perfect power (a square), and thus also a powerful number.

11857249881 is a `hidden beast` number, since 1 + 1 + 8 + 5 + 72 + 498 + 81 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4429568025 + 7427681856 = 66555^2 + 86184^2 .

It is not a de Polignac number, because 11857249881 - 2⁷ = 11857249753 is a prime.

It is a super-2 number, since 2×11857249881² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11857249841) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 108782055 + ... + 108782163.

It is an arithmetic number, because the mean of its divisors is an integer number (292704307).

Almost surely, 2^11857249881 is an apocalyptic number.

11857249881 is the 108891-st square number.

11857249881 is the 54446-th centered octagonal number.

It is an amenable number.

11857249881 is a deficient number, since it is larger than the sum of its proper divisors (6583121460).

11857249881 is an frugal number, since it uses more digits than its factorization.

11857249881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 149 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 54.

The spelling of 11857249881 in words is "eleven billion, eight hundred fifty-seven million, two hundred forty-nine thousand, eight hundred eighty-one".