81759375 has 120 divisors (see below), whose sum is σ = 170145360. Its totient is φ = 38880000.

The previous prime is 81759361. The next prime is 81759397. The reversal of 81759375 is 57395718.

It is not a de Polignac number, because 81759375 - 2¹¹ = 81757327 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81759375.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 4303116 + ... + 4303134.

It is an arithmetic number, because the mean of its divisors is an integer number (1417878).

Almost surely, 2^81759375 is an apocalyptic number.

81759375 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81759375 is an abundant number, since it is smaller than the sum of its proper divisors (88385985).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81759375 is an equidigital number, since it uses as much as digits as its factorization.

81759375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 44 counting only the distinct ones).

The product of its digits is 264600, while the sum is 45.

The square root of 81759375 is about 9042.0890838346. The cubic root of 81759375 is about 434.0227765942.

The spelling of 81759375 in words is "eighty-one million, seven hundred fifty-nine thousand, three hundred seventy-five".