81536453 has 4 divisors (see below), whose sum is σ = 82568640. Its totient is φ = 80504268.

The previous prime is 81536431. The next prime is 81536459. The reversal of 81536453 is 35463518.

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 a cyclic number.

It is not a de Polignac number, because 81536453 - 2¹⁸ = 81274309 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81536459) 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, 515975 + ... + 516132.

It is an arithmetic number, because the mean of its divisors is an integer number (20642160).

Almost surely, 2^81536453 is an apocalyptic number.

It is an amenable number.

81536453 is a deficient number, since it is larger than the sum of its proper divisors (1032187).

81536453 is a wasteful number, since it uses less digits than its factorization.

81536453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1032186.

The product of its digits is 43200, while the sum is 35.

The square root of 81536453 is about 9029.7537618697. The cubic root of 81536453 is about 433.6279542129.

The spelling of 81536453 in words is "eighty-one million, five hundred thirty-six thousand, four hundred fifty-three".