194878139 has 8 divisors (see below), whose sum is σ = 197191680. Its totient is φ = 192577896.

The previous prime is 194878129. The next prime is 194878181. The reversal of 194878139 is 931878491.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194878139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (194878129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27854 + ... + 34140.

It is an arithmetic number, because the mean of its divisors is an integer number (24648960).

Almost surely, 2^194878139 is an apocalyptic number.

194878139 is a deficient number, since it is larger than the sum of its proper divisors (2313541).

194878139 is a wasteful number, since it uses less digits than its factorization.

194878139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6649.

The product of its digits is 435456, while the sum is 50.

The square root of 194878139 is about 13959.8760381316. The cubic root of 194878139 is about 579.7681782625.

The spelling of 194878139 in words is "one hundred ninety-four million, eight hundred seventy-eight thousand, one hundred thirty-nine".