81140359 has 4 divisors (see below), whose sum is σ = 81166104. Its totient is φ = 81114616.

The previous prime is 81140357. The next prime is 81140369. The reversal of 81140359 is 95304118.

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 81140359 - 2¹ = 81140357 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81140359.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81140351) 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 3 ways as a sum of consecutive naturals, for example, 7357 + ... + 14710.

It is an arithmetic number, because the mean of its divisors is an integer number (20291526).

Almost surely, 2^81140359 is an apocalyptic number.

81140359 is a deficient number, since it is larger than the sum of its proper divisors (25745).

81140359 is a wasteful number, since it uses less digits than its factorization.

81140359 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25744.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 81140359 is about 9007.7943471196. The cubic root of 81140359 is about 432.9246437995.

The spelling of 81140359 in words is "eighty-one million, one hundred forty thousand, three hundred fifty-nine".