139678397 has 4 divisors (see below), whose sum is σ = 139778940. Its totient is φ = 139577856.

The previous prime is 139678391. The next prime is 139678417. The reversal of 139678397 is 793876931.

It is a happy number.

139678397 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 20016676 + 119661721 = 4474^2 + 10939^2 .

It is a cyclic number.

It is not a de Polignac number, because 139678397 - 2⁴ = 139678381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139678391) 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, 48158 + ... + 50975.

It is an arithmetic number, because the mean of its divisors is an integer number (34944735).

Almost surely, 2^139678397 is an apocalyptic number.

It is an amenable number.

139678397 is a deficient number, since it is larger than the sum of its proper divisors (100543).

139678397 is an equidigital number, since it uses as much as digits as its factorization.

139678397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100542.

The product of its digits is 1714608, while the sum is 53.

The square root of 139678397 is about 11818.5615452981. The cubic root of 139678397 is about 518.8515049447.

The spelling of 139678397 in words is "one hundred thirty-nine million, six hundred seventy-eight thousand, three hundred ninety-seven".