139166857 has 4 divisors (see below), whose sum is σ = 139195156. Its totient is φ = 139138560.

The previous prime is 139166821. The next prime is 139166873. The reversal of 139166857 is 758661931.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 758661931 = 419 ⋅1810649.

It can be written as a sum of positive squares in 2 ways, for example, as 80353296 + 58813561 = 8964^2 + 7669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139166857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139166057) 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, 4644 + ... + 17317.

It is an arithmetic number, because the mean of its divisors is an integer number (34798789).

Almost surely, 2^139166857 is an apocalyptic number.

It is an amenable number.

139166857 is a deficient number, since it is larger than the sum of its proper divisors (28299).

139166857 is an equidigital number, since it uses as much as digits as its factorization.

139166857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28298.

The product of its digits is 272160, while the sum is 46.

The square root of 139166857 is about 11796.9003132179. The cubic root of 139166857 is about 518.2173387209.

The spelling of 139166857 in words is "one hundred thirty-nine million, one hundred sixty-six thousand, eight hundred fifty-seven".