81384572 has 12 divisors (see below), whose sum is σ = 142500120. Its totient is φ = 40670256.

The previous prime is 81384533. The next prime is 81384577. The reversal of 81384572 is 27548318.

It is a super-3 number, since 3×81384572³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81384577) 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, 5054 + ... + 13722.

It is an arithmetic number, because the mean of its divisors is an integer number (11875010).

Almost surely, 2^81384572 is an apocalyptic number.

It is an amenable number.

81384572 is a deficient number, since it is larger than the sum of its proper divisors (61115548).

81384572 is a wasteful number, since it uses less digits than its factorization.

81384572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11020 (or 11018 counting only the distinct ones).

The product of its digits is 53760, while the sum is 38.

The square root of 81384572 is about 9021.3398118018. The cubic root of 81384572 is about 433.3585418603.

The spelling of 81384572 in words is "eighty-one million, three hundred eighty-four thousand, five hundred seventy-two".