998768641 has 4 divisors (see below), whose sum is σ = 1075597012. Its totient is φ = 921940272.

The previous prime is 998768599. The next prime is 998768681. The reversal of 998768641 is 146867899.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 68823616 + 929945025 = 8296^2 + 30495^2 .

It is a cyclic number.

It is not a de Polignac number, because 998768641 - 2¹⁹ = 998244353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (998768681) 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, 38414166 + ... + 38414191.

It is an arithmetic number, because the mean of its divisors is an integer number (268899253).

It is a Proth number, since it is equal to 1905 ⋅ 2¹⁹ + 1 and 1905 < 2¹⁹.

Almost surely, 2^998768641 is an apocalyptic number.

It is an amenable number.

998768641 is a deficient number, since it is larger than the sum of its proper divisors (76828371).

998768641 is a wasteful number, since it uses less digits than its factorization.

998768641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76828370.

The product of its digits is 5225472, while the sum is 58.

The square root of 998768641 is about 31603.3011092196. The cubic root of 998768641 is about 999.5893784130.

The spelling of 998768641 in words is "nine hundred ninety-eight million, seven hundred sixty-eight thousand, six hundred forty-one".