194978131 has 2 divisors, whose sum is σ = 194978132. Its totient is φ = 194978130.

The previous prime is 194978129. The next prime is 194978237. The reversal of 194978131 is 131879491.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 194978131 - 2¹ = 194978129 is a prime.

It is a super-2 number, since 2×194978131² = 76032943136506322, which contains 22 as substring.

Together with 194978129, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (194978431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97489065 + 97489066.

It is an arithmetic number, because the mean of its divisors is an integer number (97489066).

Almost surely, 2^194978131 is an apocalyptic number.

194978131 is a deficient number, since it is larger than the sum of its proper divisors (1).

194978131 is an equidigital number, since it uses as much as digits as its factorization.

194978131 is an odious number, because the sum of its binary digits is odd.

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

The square root of 194978131 is about 13963.4569860046. The cubic root of 194978131 is about 579.8673210185.

The spelling of 194978131 in words is "one hundred ninety-four million, nine hundred seventy-eight thousand, one hundred thirty-one".