978139 has 4 divisors (see below), whose sum is σ = 1029640. Its totient is φ = 926640.

The previous prime is 978113. The next prime is 978149. The reversal of 978139 is 931879.

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 978139 - 2⁷ = 978011 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 978098 and 978107.

It is not an unprimeable number, because it can be changed into a prime (978149) 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, 25722 + ... + 25759.

It is an arithmetic number, because the mean of its divisors is an integer number (257410).

2⁹⁷⁸¹³⁹ is an apocalyptic number.

978139 is a deficient number, since it is larger than the sum of its proper divisors (51501).

978139 is a wasteful number, since it uses less digits than its factorization.

978139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51500.

The product of its digits is 13608, while the sum is 37.

The square root of 978139 is about 989.0091000592. The cubic root of 978139 is about 99.2659245175.

The spelling of 978139 in words is "nine hundred seventy-eight thousand, one hundred thirty-nine".