139012639 has 4 divisors (see below), whose sum is σ = 139043520. Its totient is φ = 138981760.

The previous prime is 139012619. The next prime is 139012669. The reversal of 139012639 is 936210931.

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 139012639 - 2¹⁹ = 138488351 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 (139012609) 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, 7234 + ... + 18175.

It is an arithmetic number, because the mean of its divisors is an integer number (34760880).

Almost surely, 2^139012639 is an apocalyptic number.

139012639 is a deficient number, since it is larger than the sum of its proper divisors (30881).

139012639 is an equidigital number, since it uses as much as digits as its factorization.

139012639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30880.

The product of its (nonzero) digits is 8748, while the sum is 34.

The square root of 139012639 is about 11790.3621233616. The cubic root of 139012639 is about 518.0258468143.

The spelling of 139012639 in words is "one hundred thirty-nine million, twelve thousand, six hundred thirty-nine".