990251287 has 2 divisors, whose sum is σ = 990251288. Its totient is φ = 990251286.

The previous prime is 990251279. The next prime is 990251299. The reversal of 990251287 is 782152099.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 990251287 - 2³ = 990251279 is a prime.

It is a super-2 number, since 2×990251287² = 1961195222810312738, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990251267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495125643 + 495125644.

It is an arithmetic number, because the mean of its divisors is an integer number (495125644).

Almost surely, 2^990251287 is an apocalyptic number.

990251287 is a deficient number, since it is larger than the sum of its proper divisors (1).

990251287 is an equidigital number, since it uses as much as digits as its factorization.

990251287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 990251287 is about 31468.2584043032. The cubic root of 990251287 is about 996.7398117231.

The spelling of 990251287 in words is "nine hundred ninety million, two hundred fifty-one thousand, two hundred eighty-seven".