139979 has 4 divisors (see below), whose sum is σ = 159984. Its totient is φ = 119976.

The previous prime is 139969. The next prime is 139981. The reversal of 139979 is 979931.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139979 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139979.

It is not an unprimeable number, because it can be changed into a prime (139939) 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, 9992 + ... + 10005.

It is an arithmetic number, because the mean of its divisors is an integer number (39996).

2¹³⁹⁹⁷⁹ is an apocalyptic number.

139979 is a deficient number, since it is larger than the sum of its proper divisors (20005).

139979 is an equidigital number, since it uses as much as digits as its factorization.

139979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20004.

The product of its digits is 15309, while the sum is 38.

The square root of 139979 is about 374.1376751946. The cubic root of 139979 is about 51.9223446416.

The spelling of 139979 in words is "one hundred thirty-nine thousand, nine hundred seventy-nine".