81040253 has 4 divisors (see below), whose sum is σ = 92617440. Its totient is φ = 69463068.

The previous prime is 81040237. The next prime is 81040259. The reversal of 81040253 is 35204018.

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, and also an emirpimes, since its reverse is a distinct semiprime: 35204018 = 2 ⋅17602009.

It is a cyclic number.

It is not a de Polignac number, because 81040253 - 2⁴ = 81040237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81040259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5788583 + ... + 5788596.

It is an arithmetic number, because the mean of its divisors is an integer number (23154360).

Almost surely, 2^81040253 is an apocalyptic number.

It is an amenable number.

81040253 is a deficient number, since it is larger than the sum of its proper divisors (11577187).

81040253 is a wasteful number, since it uses less digits than its factorization.

81040253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11577186.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 81040253 is about 9002.2360000169. The cubic root of 81040253 is about 432.7465319043.

The spelling of 81040253 in words is "eighty-one million, forty thousand, two hundred fifty-three".