191461987 has 2 divisors, whose sum is σ = 191461988. Its totient is φ = 191461986.

The previous prime is 191461969. The next prime is 191461997. The reversal of 191461987 is 789164191.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191461987 is a prime.

It is not a weakly prime, because it can be changed into another prime (191461927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95730993 + 95730994.

It is an arithmetic number, because the mean of its divisors is an integer number (95730994).

Almost surely, 2^191461987 is an apocalyptic number.

191461987 is a deficient number, since it is larger than the sum of its proper divisors (1).

191461987 is an equidigital number, since it uses as much as digits as its factorization.

191461987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 46.

The square root of 191461987 is about 13836.9789694138. The cubic root of 191461987 is about 576.3604705369.

The spelling of 191461987 in words is "one hundred ninety-one million, four hundred sixty-one thousand, nine hundred eighty-seven".