981698491 has 4 divisors (see below), whose sum is σ = 991819192. Its totient is φ = 971577792.

The previous prime is 981698453. The next prime is 981698503. The reversal of 981698491 is 194896189.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194896189 = 157 ⋅1241377.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-981698491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (981698191) 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, 5060205 + ... + 5060398.

It is an arithmetic number, because the mean of its divisors is an integer number (247954798).

Almost surely, 2^981698491 is an apocalyptic number.

981698491 is a deficient number, since it is larger than the sum of its proper divisors (10120701).

981698491 is a wasteful number, since it uses less digits than its factorization.

981698491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10120700.

The product of its digits is 1119744, while the sum is 55.

The square root of 981698491 is about 31332.0680932491. The cubic root of 981698491 is about 993.8618977882.

The spelling of 981698491 in words is "nine hundred eighty-one million, six hundred ninety-eight thousand, four hundred ninety-one".