12157891 has 8 divisors (see below), whose sum is σ = 12830400. Its totient is φ = 11488680.

The previous prime is 12157889. The next prime is 12157897. The reversal of 12157891 is 19875121.

It is a happy number.

12157891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12157891 - 2¹ = 12157889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12157897) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12036 + ... + 13006.

It is an arithmetic number, because the mean of its divisors is an integer number (1603800).

Almost surely, 2^12157891 is an apocalyptic number.

12157891 is a deficient number, since it is larger than the sum of its proper divisors (672509).

12157891 is an equidigital number, since it uses as much as digits as its factorization.

12157891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1649.

The product of its digits is 5040, while the sum is 34.

The square root of 12157891 is about 3486.8167431054. The cubic root of 12157891 is about 229.9425880646.

The spelling of 12157891 in words is "twelve million, one hundred fifty-seven thousand, eight hundred ninety-one".