81263859 has 8 divisors (see below), whose sum is σ = 114725520. Its totient is φ = 50989056.

The previous prime is 81263857. The next prime is 81263863. The reversal of 81263859 is 95836218.

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

It is not a de Polignac number, because 81263859 - 2¹ = 81263857 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 81263859.

It is not an unprimeable number, because it can be changed into a prime (81263857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 796654 + ... + 796755.

It is an arithmetic number, because the mean of its divisors is an integer number (14340690).

Almost surely, 2^81263859 is an apocalyptic number.

81263859 is a deficient number, since it is larger than the sum of its proper divisors (33461661).

81263859 is a wasteful number, since it uses less digits than its factorization.

81263859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1593429.

The product of its digits is 103680, while the sum is 42.

The square root of 81263859 is about 9014.6469148825. The cubic root of 81263859 is about 433.1441773376.

The spelling of 81263859 in words is "eighty-one million, two hundred sixty-three thousand, eight hundred fifty-nine".