990228997 has 2 divisors, whose sum is σ = 990228998. Its totient is φ = 990228996.

The previous prime is 990228989. The next prime is 990229003. The reversal of 990228997 is 799822099.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 877996161 + 112232836 = 29631^2 + 10594^2 .

It is a cyclic number.

It is not a de Polignac number, because 990228997 - 2³ = 990228989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990228917) 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, 495114498 + 495114499.

It is an arithmetic number, because the mean of its divisors is an integer number (495114499).

Almost surely, 2^990228997 is an apocalyptic number.

It is an amenable number.

990228997 is a deficient number, since it is larger than the sum of its proper divisors (1).

990228997 is an equidigital number, since it uses as much as digits as its factorization.

990228997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1469664, while the sum is 55.

The square root of 990228997 is about 31467.9042359036. The cubic root of 990228997 is about 996.7323329826.

The spelling of 990228997 in words is "nine hundred ninety million, two hundred twenty-eight thousand, nine hundred ninety-seven".