194178139 has 2 divisors, whose sum is σ = 194178140. Its totient is φ = 194178138.

The previous prime is 194178107. The next prime is 194178161. The reversal of 194178139 is 931871491.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 194178139 - 2⁵ = 194178107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 194178095 and 194178104.

It is not a weakly prime, because it can be changed into another prime (194173139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97089069 + 97089070.

It is an arithmetic number, because the mean of its divisors is an integer number (97089070).

Almost surely, 2^194178139 is an apocalyptic number.

194178139 is a deficient number, since it is larger than the sum of its proper divisors (1).

194178139 is an equidigital number, since it uses as much as digits as its factorization.

194178139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 43.

The square root of 194178139 is about 13934.7816272807. The cubic root of 194178139 is about 579.0731719365.

It can be divided in two parts, 19417 and 8139, that added together give a square (27556 = 166²).

The spelling of 194178139 in words is "one hundred ninety-four million, one hundred seventy-eight thousand, one hundred thirty-nine".