81342568 has 16 divisors (see below), whose sum is σ = 152750880. Its totient is φ = 40609008.

The previous prime is 81342563. The next prime is 81342589. The reversal of 81342568 is 86524318.

It is a happy number.

It is a super-2 number, since 2×81342568² = 13233226737669248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81342563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1980 + ... + 12907.

It is an arithmetic number, because the mean of its divisors is an integer number (9546930).

Almost surely, 2^81342568 is an apocalyptic number.

It is an amenable number.

81342568 is a deficient number, since it is larger than the sum of its proper divisors (71408312).

81342568 is a wasteful number, since it uses less digits than its factorization.

81342568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15576 (or 15572 counting only the distinct ones).

The product of its digits is 46080, while the sum is 37.

The square root of 81342568 is about 9019.0114757661. The cubic root of 81342568 is about 433.2839743911.

The spelling of 81342568 in words is "eighty-one million, three hundred forty-two thousand, five hundred sixty-eight".