81353253 has 4 divisors (see below), whose sum is σ = 108471008. Its totient is φ = 54235500.

The previous prime is 81353243. The next prime is 81353263. The reversal of 81353253 is 35235318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (81353243) and next prime (81353263).

It is not a de Polignac number, because 81353253 - 2⁶ = 81353189 is a prime.

It is a super-3 number, since 3×81353253³ (a number of 25 digits) contains 333 as substring.

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 81353253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81353243) 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, 13558873 + ... + 13558878.

It is an arithmetic number, because the mean of its divisors is an integer number (27117752).

Almost surely, 2^81353253 is an apocalyptic number.

It is an amenable number.

81353253 is a deficient number, since it is larger than the sum of its proper divisors (27117755).

81353253 is a wasteful number, since it uses less digits than its factorization.

81353253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27117754.

The product of its digits is 10800, while the sum is 30.

The square root of 81353253 is about 9019.6038161329. The cubic root of 81353253 is about 433.3029453378.

The spelling of 81353253 in words is "eighty-one million, three hundred fifty-three thousand, two hundred fifty-three".