291290887 has 2 divisors, whose sum is σ = 291290888. Its totient is φ = 291290886.

The previous prime is 291290863. The next prime is 291290941. The reversal of 291290887 is 788092192.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 291290887 - 2¹⁵ = 291258119 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291290807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145645443 + 145645444.

It is an arithmetic number, because the mean of its divisors is an integer number (145645444).

Almost surely, 2^291290887 is an apocalyptic number.

291290887 is a deficient number, since it is larger than the sum of its proper divisors (1).

291290887 is an equidigital number, since it uses as much as digits as its factorization.

291290887 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 46.

The square root of 291290887 is about 17067.2460285777. The cubic root of 291290887 is about 662.8912696200.

The spelling of 291290887 in words is "two hundred ninety-one million, two hundred ninety thousand, eight hundred eighty-seven".