11971857 has 4 divisors (see below), whose sum is σ = 15962480. Its totient is φ = 7981236.

The previous prime is 11971853. The next prime is 11971871. The reversal of 11971857 is 75817911.

11971857 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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.

It is not a de Polignac number, because 11971857 - 2² = 11971853 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11971853) 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, 1995307 + ... + 1995312.

It is an arithmetic number, because the mean of its divisors is an integer number (3990620).

Almost surely, 2^11971857 is an apocalyptic number.

It is an amenable number.

11971857 is a deficient number, since it is larger than the sum of its proper divisors (3990623).

11971857 is an equidigital number, since it uses as much as digits as its factorization.

11971857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3990622.

The product of its digits is 17640, while the sum is 39.

The square root of 11971857 is about 3460.0371385290. The cubic root of 11971857 is about 228.7637323417.

The spelling of 11971857 in words is "eleven million, nine hundred seventy-one thousand, eight hundred fifty-seven".