197291971 has 2 divisors, whose sum is σ = 197291972. Its totient is φ = 197291970.

The previous prime is 197291933. The next prime is 197291977. The reversal of 197291971 is 179192791.

It is a strong prime.

It is an emirp because it is prime and its reverse (179192791) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-197291971 is a prime.

It is not a weakly prime, because it can be changed into another prime (197291977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98645985 + 98645986.

It is an arithmetic number, because the mean of its divisors is an integer number (98645986).

Almost surely, 2^197291971 is an apocalyptic number.

197291971 is the 8110-th hex number.

197291971 is a deficient number, since it is larger than the sum of its proper divisors (1).

197291971 is an equidigital number, since it uses as much as digits as its factorization.

197291971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 71442, while the sum is 46.

The square root of 197291971 is about 14046.0660328791. The cubic root of 197291971 is about 582.1521027959.

The spelling of 197291971 in words is "one hundred ninety-seven million, two hundred ninety-one thousand, nine hundred seventy-one".