194131387 has 2 divisors, whose sum is σ = 194131388. Its totient is φ = 194131386.

The previous prime is 194131363. The next prime is 194131391. The reversal of 194131387 is 783131491.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-194131387 is a prime.

It is not a weakly prime, because it can be changed into another prime (194131397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97065693 + 97065694.

It is an arithmetic number, because the mean of its divisors is an integer number (97065694).

Almost surely, 2^194131387 is an apocalyptic number.

194131387 is a deficient number, since it is larger than the sum of its proper divisors (1).

194131387 is an equidigital number, since it uses as much as digits as its factorization.

194131387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 37.

The square root of 194131387 is about 13933.1039973152. The cubic root of 194131387 is about 579.0266939925.

The spelling of 194131387 in words is "one hundred ninety-four million, one hundred thirty-one thousand, three hundred eighty-seven".