81363851 has 8 divisors (see below), whose sum is σ = 85141584. Its totient is φ = 77669280.

The previous prime is 81363847. The next prime is 81363859. The reversal of 81363851 is 15836318.

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

It is a cyclic number.

It is not a de Polignac number, because 81363851 - 2² = 81363847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81363859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18785 + ... + 22706.

It is an arithmetic number, because the mean of its divisors is an integer number (10642698).

Almost surely, 2^81363851 is an apocalyptic number.

81363851 is a deficient number, since it is larger than the sum of its proper divisors (3777733).

81363851 is a wasteful number, since it uses less digits than its factorization.

81363851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41581.

The product of its digits is 17280, while the sum is 35.

The square root of 81363851 is about 9020.1912950890. The cubic root of 81363851 is about 433.3217601774.

The spelling of 81363851 in words is "eighty-one million, three hundred sixty-three thousand, eight hundred fifty-one".