998940997 has 4 divisors (see below), whose sum is σ = 1000240780. Its totient is φ = 997641216.

The previous prime is 998940923. The next prime is 998941003. The reversal of 998940997 is 799049899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 799049899 = 149 ⋅5362751.

It can be written as a sum of positive squares in 2 ways, for example, as 766957636 + 231983361 = 27694^2 + 15231^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-998940997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998940907) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 648738 + ... + 650275.

It is an arithmetic number, because the mean of its divisors is an integer number (250060195).

Almost surely, 2^998940997 is an apocalyptic number.

It is an amenable number.

998940997 is a deficient number, since it is larger than the sum of its proper divisors (1299783).

998940997 is a wasteful number, since it uses less digits than its factorization.

998940997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1299782.

The product of its (nonzero) digits is 13226976, while the sum is 64.

The square root of 998940997 is about 31606.0278586222. The cubic root of 998940997 is about 999.6468743169.

The spelling of 998940997 in words is "nine hundred ninety-eight million, nine hundred forty thousand, nine hundred ninety-seven".