998406503 has 4 divisors (see below), whose sum is σ = 1011044640. Its totient is φ = 985768368.

The previous prime is 998406499. The next prime is 998406569. The reversal of 998406503 is 305604899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 305604899 = 4283 ⋅71353.

It is a cyclic number.

It is not a de Polignac number, because 998406503 - 2² = 998406499 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 (998406593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6318950 + ... + 6319107.

It is an arithmetic number, because the mean of its divisors is an integer number (252761160).

Almost surely, 2^998406503 is an apocalyptic number.

998406503 is a deficient number, since it is larger than the sum of its proper divisors (12638137).

998406503 is a wasteful number, since it uses less digits than its factorization.

998406503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12638136.

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 998406503 is about 31597.5711566570. The cubic root of 998406503 is about 999.4685519463.

The spelling of 998406503 in words is "nine hundred ninety-eight million, four hundred six thousand, five hundred three".