81801142 has 8 divisors (see below), whose sum is σ = 122994432. Its totient is φ = 40803000.

The previous prime is 81801107. The next prime is 81801143. The reversal of 81801142 is 24110818.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81801143) 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, 47734 + ... + 49417.

It is an arithmetic number, because the mean of its divisors is an integer number (15374304).

Almost surely, 2^81801142 is an apocalyptic number.

81801142 is a deficient number, since it is larger than the sum of its proper divisors (41193290).

81801142 is a wasteful number, since it uses less digits than its factorization.

81801142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97574.

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 81801142 is about 9044.3983768961. The cubic root of 81801142 is about 434.0966712528.

The spelling of 81801142 in words is "eighty-one million, eight hundred one thousand, one hundred forty-two".