291224987 has 2 divisors, whose sum is σ = 291224988. Its totient is φ = 291224986.

The previous prime is 291224971. The next prime is 291225007. The reversal of 291224987 is 789422192.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 291224987 - 2⁴ = 291224971 is a prime.

It is not a weakly prime, because it can be changed into another prime (291224917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145612493 + 145612494.

It is an arithmetic number, because the mean of its divisors is an integer number (145612494).

Almost surely, 2^291224987 is an apocalyptic number.

291224987 is a deficient number, since it is larger than the sum of its proper divisors (1).

291224987 is an equidigital number, since it uses as much as digits as its factorization.

291224987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 291224987 is about 17065.3153208489. The cubic root of 291224987 is about 662.8412762613.

The spelling of 291224987 in words is "two hundred ninety-one million, two hundred twenty-four thousand, nine hundred eighty-seven".