81581352 has 32 divisors (see below), whose sum is σ = 204310080. Its totient is φ = 27146240.

The previous prime is 81581347. The next prime is 81581389. The reversal of 81581352 is 25318518.

It is a happy 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, 12733 + ... + 18035.

It is an arithmetic number, because the mean of its divisors is an integer number (6384690).

Almost surely, 2^81581352 is an apocalyptic number.

It is an amenable number.

81581352 is an abundant number, since it is smaller than the sum of its proper divisors (122728728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81581352 is a wasteful number, since it uses less digits than its factorization.

81581352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5953 (or 5949 counting only the distinct ones).

The product of its digits is 9600, while the sum is 33.

The square root of 81581352 is about 9032.2395893820. The cubic root of 81581352 is about 433.7075337065.

The spelling of 81581352 in words is "eighty-one million, five hundred eighty-one thousand, three hundred fifty-two".