990217799 has 2 divisors, whose sum is σ = 990217800. Its totient is φ = 990217798.

The previous prime is 990217777. The next prime is 990217829. The reversal of 990217799 is 997712099.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-990217799 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 990217799.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (990217729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495108899 + 495108900.

It is an arithmetic number, because the mean of its divisors is an integer number (495108900).

Almost surely, 2^990217799 is an apocalyptic number.

990217799 is a deficient number, since it is larger than the sum of its proper divisors (1).

990217799 is an equidigital number, since it uses as much as digits as its factorization.

990217799 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 642978, while the sum is 53.

The square root of 990217799 is about 31467.7263080763. The cubic root of 990217799 is about 996.7285757875.

The spelling of 990217799 in words is "nine hundred ninety million, two hundred seventeen thousand, seven hundred ninety-nine".