981971851 has 16 divisors (see below), whose sum is σ = 1185096960. Its totient is φ = 794841120.

The previous prime is 981971843. The next prime is 981971873. The reversal of 981971851 is 158179189.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 981971851 - 2³ = 981971843 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 981971795 and 981971804.

It is not an unprimeable number, because it can be changed into a prime (981975851) 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 15 ways as a sum of consecutive naturals, for example, 30516 + ... + 53806.

It is an arithmetic number, because the mean of its divisors is an integer number (74068560).

Almost surely, 2^981971851 is an apocalyptic number.

981971851 is a deficient number, since it is larger than the sum of its proper divisors (203125109).

981971851 is a wasteful number, since it uses less digits than its factorization.

981971851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23634.

The product of its digits is 181440, while the sum is 49.

The square root of 981971851 is about 31336.4300934232. The cubic root of 981971851 is about 993.9541382190.

The spelling of 981971851 in words is "nine hundred eighty-one million, nine hundred seventy-one thousand, eight hundred fifty-one".