81129142 has 8 divisors (see below), whose sum is σ = 126984816. Its totient is φ = 38800872.

The previous prime is 81129137. The next prime is 81129143. The reversal of 81129142 is 24192118.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81129142.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81129143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 881793 + ... + 881884.

It is an arithmetic number, because the mean of its divisors is an integer number (15873102).

Almost surely, 2^81129142 is an apocalyptic number.

81129142 is a deficient number, since it is larger than the sum of its proper divisors (45855674).

81129142 is a wasteful number, since it uses less digits than its factorization.

81129142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1763702.

The product of its digits is 1152, while the sum is 28.

The square root of 81129142 is about 9007.1716981525. The cubic root of 81129142 is about 432.9046934338.

The spelling of 81129142 in words is "eighty-one million, one hundred twenty-nine thousand, one hundred forty-two".