9981986390 has 64 divisors (see below), whose sum is σ = 19399564800. Its totient is φ = 3684189696.

The previous prime is 9981986363. The next prime is 9981986393. The reversal of 9981986390 is 936891899.

It is a Smith number, since the sum of its digits (62) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9981986393) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4402037 + ... + 4404303.

It is an arithmetic number, because the mean of its divisors is an integer number (303118200).

Almost surely, 2^9981986390 is an apocalyptic number.

9981986390 is a deficient number, since it is larger than the sum of its proper divisors (9417578410).

9981986390 is a wasteful number, since it uses less digits than its factorization.

9981986390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2789.

The product of its (nonzero) digits is 7558272, while the sum is 62.

The square root of 9981986390 is about 99909.8913521579. The cubic root of 9981986390 is about 2153.1402742746.

The spelling of 9981986390 in words is "nine billion, nine hundred eighty-one million, nine hundred eighty-six thousand, three hundred ninety".