81364547 has 16 divisors (see below), whose sum is σ = 93235968. Its totient is φ = 70282080.

The previous prime is 81364531. The next prime is 81364583. The reversal of 81364547 is 74546318.

It is not a de Polignac number, because 81364547 - 2⁴ = 81364531 is a prime.

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 81364547.

It is not an unprimeable number, because it can be changed into a prime (81364447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40253 + ... + 42225.

It is an arithmetic number, because the mean of its divisors is an integer number (5827248).

Almost surely, 2^81364547 is an apocalyptic number.

81364547 is a deficient number, since it is larger than the sum of its proper divisors (11871421).

81364547 is a wasteful number, since it uses less digits than its factorization.

81364547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2170.

The product of its digits is 80640, while the sum is 38.

The square root of 81364547 is about 9020.2298751196. The cubic root of 81364547 is about 433.3229957429.

The spelling of 81364547 in words is "eighty-one million, three hundred sixty-four thousand, five hundred forty-seven".