981491138 has 16 divisors (see below), whose sum is σ = 1525367160. Its totient is φ = 473088000.

The previous prime is 981491117. The next prime is 981491171. The reversal of 981491138 is 831194189.

It can be written as a sum of positive squares in 4 ways, for example, as 955613569 + 25877569 = 30913^2 + 5087^2 .

It is a Curzon number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 25538 + ... + 51138.

Almost surely, 2^981491138 is an apocalyptic number.

981491138 is a deficient number, since it is larger than the sum of its proper divisors (543876022).

981491138 is a wasteful number, since it uses less digits than its factorization.

981491138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26293.

The product of its digits is 62208, while the sum is 44.

The square root of 981491138 is about 31328.7589604185. The cubic root of 981491138 is about 993.7919188150.

The spelling of 981491138 in words is "nine hundred eighty-one million, four hundred ninety-one thousand, one hundred thirty-eight".