291897863 has 2 divisors, whose sum is σ = 291897864. Its totient is φ = 291897862.

The previous prime is 291897833. The next prime is 291897869. The reversal of 291897863 is 368798192.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 291897863 - 2⁶ = 291897799 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291897869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145948931 + 145948932.

It is an arithmetic number, because the mean of its divisors is an integer number (145948932).

Almost surely, 2^291897863 is an apocalyptic number.

291897863 is a deficient number, since it is larger than the sum of its proper divisors (1).

291897863 is an equidigital number, since it uses as much as digits as its factorization.

291897863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 53.

The square root of 291897863 is about 17085.0186713389. The cubic root of 291897863 is about 663.3513823584.

The spelling of 291897863 in words is "two hundred ninety-one million, eight hundred ninety-seven thousand, eight hundred sixty-three".