81364645 has 8 divisors (see below), whose sum is σ = 97812000. Its totient is φ = 64975440.

The previous prime is 81364627. The next prime is 81364681. The reversal of 81364645 is 54646318.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81364645 - 2¹¹ = 81362597 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11395 + ... + 17104.

It is an arithmetic number, because the mean of its divisors is an integer number (12226500).

Almost surely, 2^81364645 is an apocalyptic number.

It is an amenable number.

81364645 is a deficient number, since it is larger than the sum of its proper divisors (16447355).

81364645 is a wasteful number, since it uses less digits than its factorization.

81364645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29075.

The product of its digits is 69120, while the sum is 37.

The square root of 81364645 is about 9020.2353073520. The cubic root of 81364645 is about 433.3231697156.

The spelling of 81364645 in words is "eighty-one million, three hundred sixty-four thousand, six hundred forty-five".