81353975 has 6 divisors (see below), whose sum is σ = 100878960. Its totient is φ = 65083160.

The previous prime is 81353969. The next prime is 81353977. The reversal of 81353975 is 57935318.

It is a happy number.

It is not a de Polignac number, because 81353975 - 2⁸ = 81353719 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81353977) 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 5 ways as a sum of consecutive naturals, for example, 1627055 + ... + 1627104.

It is an arithmetic number, because the mean of its divisors is an integer number (16813160).

Almost surely, 2^81353975 is an apocalyptic number.

81353975 is a deficient number, since it is larger than the sum of its proper divisors (19524985).

81353975 is a wasteful number, since it uses less digits than its factorization.

81353975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3254169 (or 3254164 counting only the distinct ones).

The product of its digits is 113400, while the sum is 41.

The square root of 81353975 is about 9019.6438399751. The cubic root of 81353975 is about 433.3042271706.

It can be divided in two parts, 81353 and 975, that added together give a palindrome (82328).

The spelling of 81353975 in words is "eighty-one million, three hundred fifty-three thousand, nine hundred seventy-five".