981997578 has 12 divisors (see below), whose sum is σ = 2127661458. Its totient is φ = 327332520.

The previous prime is 981997547. The next prime is 981997607. The reversal of 981997578 is 875799189.

It can be written as a sum of positive squares in only one way, i.e., 783272169 + 198725409 = 27987^2 + 14097^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27277693 + ... + 27277728.

Almost surely, 2^981997578 is an apocalyptic number.

981997578 is an abundant number, since it is smaller than the sum of its proper divisors (1145663880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

981997578 is a wasteful number, since it uses less digits than its factorization.

981997578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54555429 (or 54555426 counting only the distinct ones).

The product of its digits is 11430720, while the sum is 63.

The square root of 981997578 is about 31336.8405873981. The cubic root of 981997578 is about 993.9628184525.

The spelling of 981997578 in words is "nine hundred eighty-one million, nine hundred ninety-seven thousand, five hundred seventy-eight".