998400817 has 2 divisors, whose sum is σ = 998400818. Its totient is φ = 998400816.

The previous prime is 998400761. The next prime is 998400833. The reversal of 998400817 is 718004899.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 920272896 + 78127921 = 30336^2 + 8839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998400817 is a prime.

It is not a weakly prime, because it can be changed into another prime (998400217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499200408 + 499200409.

It is an arithmetic number, because the mean of its divisors is an integer number (499200409).

Almost surely, 2^998400817 is an apocalyptic number.

It is an amenable number.

998400817 is a deficient number, since it is larger than the sum of its proper divisors (1).

998400817 is an equidigital number, since it uses as much as digits as its factorization.

998400817 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 998400817 is about 31597.4811812587. The cubic root of 998400817 is about 999.4666545932.

The spelling of 998400817 in words is "nine hundred ninety-eight million, four hundred thousand, eight hundred seventeen".