81799718 has 72 divisors (see below), whose sum is σ = 168982200. Its totient is φ = 29352960.

The previous prime is 81799709. The next prime is 81799721.

81799718 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 181958 + ... + 182406.

It is an arithmetic number, because the mean of its divisors is an integer number (2346975).

Almost surely, 2^81799718 is an apocalyptic number.

81799718 is an abundant number, since it is smaller than the sum of its proper divisors (87182482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81799718 is a wasteful number, since it uses less digits than its factorization.

81799718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502 (or 482 counting only the distinct ones).

The product of its digits is 254016, while the sum is 50.

The square root of 81799718 is about 9044.3196537938. The cubic root of 81799718 is about 434.0941523098.

The spelling of 81799718 in words is "eighty-one million, seven hundred ninety-nine thousand, seven hundred eighteen".