81983387 has 4 divisors (see below), whose sum is σ = 82046496. Its totient is φ = 81920280.

The previous prime is 81983383. The next prime is 81983393. The reversal of 81983387 is 78338918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81983387 - 2² = 81983383 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81983381) 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, 29564 + ... + 32217.

It is an arithmetic number, because the mean of its divisors is an integer number (20511624).

Almost surely, 2^81983387 is an apocalyptic number.

81983387 is a deficient number, since it is larger than the sum of its proper divisors (63109).

81983387 is a wasteful number, since it uses less digits than its factorization.

81983387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63108.

The product of its digits is 290304, while the sum is 47.

The square root of 81983387 is about 9054.4677922007. The cubic root of 81983387 is about 434.4188072169.

The spelling of 81983387 in words is "eighty-one million, nine hundred eighty-three thousand, three hundred eighty-seven".