11997857 has 4 divisors (see below), whose sum is σ = 12040836. Its totient is φ = 11954880.

The previous prime is 11997847. The next prime is 11997863. The reversal of 11997857 is 75879911.

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 4648336 + 7349521 = 2156^2 + 2711^2 .

It is a cyclic number.

It is not a de Polignac number, because 11997857 - 2⁴ = 11997841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11997847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21068 + ... + 21629.

It is an arithmetic number, because the mean of its divisors is an integer number (3010209).

Almost surely, 2^11997857 is an apocalyptic number.

It is an amenable number.

11997857 is a deficient number, since it is larger than the sum of its proper divisors (42979).

11997857 is an equidigital number, since it uses as much as digits as its factorization.

11997857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42978.

The product of its digits is 158760, while the sum is 47.

The square root of 11997857 is about 3463.7922859202. The cubic root of 11997857 is about 228.9292192403.

The spelling of 11997857 in words is "eleven million, nine hundred ninety-seven thousand, eight hundred fifty-seven".