9981881386 has 8 divisors (see below), whose sum is σ = 15377493060. Its totient is φ = 4856050368.

The previous prime is 9981881383. The next prime is 9981881387. The reversal of 9981881386 is 6831881899.

It can be written as a sum of positive squares in 2 ways, for example, as 9953055225 + 28826161 = 99765^2 + 5369^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (9981881383) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67445071 + ... + 67445218.

Almost surely, 2^9981881386 is an apocalyptic number.

9981881386 is a deficient number, since it is larger than the sum of its proper divisors (5395611674).

9981881386 is a wasteful number, since it uses less digits than its factorization.

9981881386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134890328.

The product of its digits is 5971968, while the sum is 61.

The square root of 9981881386 is about 99909.3658572608. The cubic root of 9981881386 is about 2153.1327243700.

It can be divided in two parts, 998 and 1881386, that added together give a square (1882384 = 1372²).

The spelling of 9981881386 in words is "nine billion, nine hundred eighty-one million, eight hundred eighty-one thousand, three hundred eighty-six".