81039142 has 16 divisors (see below), whose sum is σ = 128502000. Its totient is φ = 38223360.

The previous prime is 81039109. The next prime is 81039157. The reversal of 81039142 is 24193018.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81039142.

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, 4734 + ... + 13582.

It is an arithmetic number, because the mean of its divisors is an integer number (8031375).

Almost surely, 2^81039142 is an apocalyptic number.

81039142 is a deficient number, since it is larger than the sum of its proper divisors (47462858).

81039142 is a wasteful number, since it uses less digits than its factorization.

81039142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9111.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 81039142 is about 9002.1742929139. The cubic root of 81039142 is about 432.7445543538.

The spelling of 81039142 in words is "eighty-one million, thirty-nine thousand, one hundred forty-two".