81364507 has 4 divisors (see below), whose sum is σ = 92988016. Its totient is φ = 69741000.

The previous prime is 81364483. The next prime is 81364513. The reversal of 81364507 is 70546318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 70546318 = 2 ⋅35273159.

It is a de Polignac number, because none of the positive numbers 2^k-81364507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81364007) 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, 5811744 + ... + 5811757.

It is an arithmetic number, because the mean of its divisors is an integer number (23247004).

Almost surely, 2^81364507 is an apocalyptic number.

81364507 is a deficient number, since it is larger than the sum of its proper divisors (11623509).

81364507 is a wasteful number, since it uses less digits than its factorization.

81364507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11623508.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 81364507 is about 9020.2276578809. The cubic root of 81364507 is about 433.3229247336.

The spelling of 81364507 in words is "eighty-one million, three hundred sixty-four thousand, five hundred seven".