81853178 has 32 divisors (see below), whose sum is σ = 143424000. Its totient is φ = 34639920.

The previous prime is 81853171. The next prime is 81853193. The reversal of 81853178 is 87135818.

It is not an unprimeable number, because it can be changed into a prime (81853171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23003 + ... + 26321.

It is an arithmetic number, because the mean of its divisors is an integer number (4482000).

Almost surely, 2^81853178 is an apocalyptic number.

81853178 is a deficient number, since it is larger than the sum of its proper divisors (61570822).

81853178 is a wasteful number, since it uses less digits than its factorization.

81853178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3410.

The product of its digits is 53760, while the sum is 41.

The square root of 81853178 is about 9047.2746172535. The cubic root of 81853178 is about 434.1886987631.

The spelling of 81853178 in words is "eighty-one million, eight hundred fifty-three thousand, one hundred seventy-eight".