12139857 has 6 divisors (see below), whose sum is σ = 17535362. Its totient is φ = 8093232.

The previous prime is 12139849. The next prime is 12139861. The reversal of 12139857 is 75893121.

It can be written as a sum of positive squares in only one way, i.e., 7817616 + 4322241 = 2796^2 + 2079^2 .

It is not a de Polignac number, because 12139857 - 2³ = 12139849 is a prime.

It is a super-2 number, since 2×12139857² = 294752255960898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12139807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 674428 + ... + 674445.

Almost surely, 2^12139857 is an apocalyptic number.

It is an amenable number.

12139857 is a deficient number, since it is larger than the sum of its proper divisors (5395505).

12139857 is a wasteful number, since it uses less digits than its factorization.

12139857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348879 (or 1348876 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 12139857 is about 3484.2297570625. The cubic root of 12139857 is about 229.8288392613.

It can be divided in two parts, 12139 and 857, that added together give a square (12996 = 114²).

The spelling of 12139857 in words is "twelve million, one hundred thirty-nine thousand, eight hundred fifty-seven".