998640647 has 2 divisors, whose sum is σ = 998640648. Its totient is φ = 998640646.

The previous prime is 998640613. The next prime is 998640653. The reversal of 998640647 is 746046899.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 998640647 - 2⁶ = 998640583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998640697) 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, 499320323 + 499320324.

It is an arithmetic number, because the mean of its divisors is an integer number (499320324).

Almost surely, 2^998640647 is an apocalyptic number.

998640647 is a deficient number, since it is larger than the sum of its proper divisors (1).

998640647 is an equidigital number, since it uses as much as digits as its factorization.

998640647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2612736, while the sum is 53.

The square root of 998640647 is about 31601.2760343629. The cubic root of 998640647 is about 999.5466768625.

The spelling of 998640647 in words is "nine hundred ninety-eight million, six hundred forty thousand, six hundred forty-seven".