139771978 has 8 divisors (see below), whose sum is σ = 209816100. Its totient is φ = 69833280.

The previous prime is 139771913. The next prime is 139771991. The reversal of 139771978 is 879177931.

It can be written as a sum of positive squares in 2 ways, for example, as 115928289 + 23843689 = 10767^2 + 4883^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22953 + ... + 28396.

Almost surely, 2^139771978 is an apocalyptic number.

139771978 is a deficient number, since it is larger than the sum of its proper divisors (70044122).

139771978 is a wasteful number, since it uses less digits than its factorization.

139771978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52712.

The product of its digits is 666792, while the sum is 52.

The square root of 139771978 is about 11822.5199513471. The cubic root of 139771978 is about 518.9673515473.

The spelling of 139771978 in words is "one hundred thirty-nine million, seven hundred seventy-one thousand, nine hundred seventy-eight".