139978 has 16 divisors (see below), whose sum is σ = 233280. Its totient is φ = 62656.

The previous prime is 139969. The next prime is 139981. The reversal of 139978 is 879931.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 693 + ... + 871.

It is an arithmetic number, because the mean of its divisors is an integer number (14580).

2¹³⁹⁹⁷⁸ is an apocalyptic number.

139978 is a deficient number, since it is larger than the sum of its proper divisors (93302).

139978 is a wasteful number, since it uses less digits than its factorization.

139978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221.

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

The square root of 139978 is about 374.1363387857. The cubic root of 139978 is about 51.9222209982.

The spelling of 139978 in words is "one hundred thirty-nine thousand, nine hundred seventy-eight".