998934721 has 4 divisors (see below), whose sum is σ = 1000597444. Its totient is φ = 997272000.

The previous prime is 998934659. The next prime is 998934733. The reversal of 998934721 is 127439899.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127439899 = 4423 ⋅28813.

It can be written as a sum of positive squares in 2 ways, for example, as 410629696 + 588305025 = 20264^2 + 24255^2 .

It is a cyclic number.

It is not a de Polignac number, because 998934721 - 2¹³ = 998926529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (998931721) 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 in 3 ways as a sum of consecutive naturals, for example, 830460 + ... + 831661.

It is an arithmetic number, because the mean of its divisors is an integer number (250149361).

Almost surely, 2^998934721 is an apocalyptic number.

It is an amenable number.

998934721 is a deficient number, since it is larger than the sum of its proper divisors (1662723).

998934721 is a wasteful number, since it uses less digits than its factorization.

998934721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662722.

The product of its digits is 979776, while the sum is 52.

The square root of 998934721 is about 31605.9285736078. The cubic root of 998934721 is about 999.6447808343.

The spelling of 998934721 in words is "nine hundred ninety-eight million, nine hundred thirty-four thousand, seven hundred twenty-one".