139428187 has 4 divisors (see below), whose sum is σ = 139479120. Its totient is φ = 139377256.

The previous prime is 139428161. The next prime is 139428197. The reversal of 139428187 is 781824931.

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 139428187 - 2¹⁹ = 138903899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139428197) 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 3 ways as a sum of consecutive naturals, for example, 21112 + ... + 26917.

It is an arithmetic number, because the mean of its divisors is an integer number (34869780).

Almost surely, 2^139428187 is an apocalyptic number.

139428187 is a deficient number, since it is larger than the sum of its proper divisors (50933).

139428187 is an equidigital number, since it uses as much as digits as its factorization.

139428187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50932.

The product of its digits is 96768, while the sum is 43.

The square root of 139428187 is about 11807.9713329598. The cubic root of 139428187 is about 518.5415084743.

The spelling of 139428187 in words is "one hundred thirty-nine million, four hundred twenty-eight thousand, one hundred eighty-seven".