139428391 has 4 divisors (see below), whose sum is σ = 139464712. Its totient is φ = 139392072.

The previous prime is 139428353. The next prime is 139428431. The reversal of 139428391 is 193824931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 139428391 - 2⁹ = 139427879 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 (139458391) 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, 11616 + ... + 20341.

It is an arithmetic number, because the mean of its divisors is an integer number (34866178).

Almost surely, 2^139428391 is an apocalyptic number.

139428391 is a deficient number, since it is larger than the sum of its proper divisors (36321).

139428391 is an equidigital number, since it uses as much as digits as its factorization.

139428391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36320.

The product of its digits is 46656, while the sum is 40.

The square root of 139428391 is about 11807.9799711890. The cubic root of 139428391 is about 518.5417613701.

The spelling of 139428391 in words is "one hundred thirty-nine million, four hundred twenty-eight thousand, three hundred ninety-one".