291971 has 2 divisors, whose sum is σ = 291972. Its totient is φ = 291970.

The previous prime is 291923. The next prime is 291979. The reversal of 291971 is 179192.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-291971 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291971.

It is not a weakly prime, because it can be changed into another prime (291979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145985 + 145986.

It is an arithmetic number, because the mean of its divisors is an integer number (145986).

2²⁹¹⁹⁷¹ is an apocalyptic number.

291971 is a deficient number, since it is larger than the sum of its proper divisors (1).

291971 is an equidigital number, since it uses as much as digits as its factorization.

291971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1134, while the sum is 29.

The square root of 291971 is about 540.3434093241. The cubic root of 291971 is about 66.3406780136.

The spelling of 291971 in words is "two hundred ninety-one thousand, nine hundred seventy-one".