1981574113 has 4 divisors (see below), whose sum is σ = 1981943748. Its totient is φ = 1981204480.

The previous prime is 1981574099. The next prime is 1981574129. The reversal of 1981574113 is 3114751891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3114751891 = 7507 ⋅414913.

It can be written as a sum of positive squares in 2 ways, for example, as 1589058769 + 392515344 = 39863^2 + 19812^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1981574113 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981571113) 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 3 ways as a sum of consecutive naturals, for example, 176656 + ... + 187537.

It is an arithmetic number, because the mean of its divisors is an integer number (495485937).

Almost surely, 2^1981574113 is an apocalyptic number.

It is an amenable number.

1981574113 is a deficient number, since it is larger than the sum of its proper divisors (369635).

1981574113 is an equidigital number, since it uses as much as digits as its factorization.

1981574113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369634.

The product of its digits is 30240, while the sum is 40.

The square root of 1981574113 is about 44514.8751879639. The cubic root of 1981574113 is about 1256.0399126649.

The spelling of 1981574113 in words is "one billion, nine hundred eighty-one million, five hundred seventy-four thousand, one hundred thirteen".