81868446 has 24 divisors (see below), whose sum is σ = 193507704. Its totient is φ = 24808560.

The previous prime is 81868441. The next prime is 81868469. The reversal of 81868446 is 64486818.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81868441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 206541 + ... + 206936.

It is an arithmetic number, because the mean of its divisors is an integer number (8062821).

Almost surely, 2^81868446 is an apocalyptic number.

81868446 is an abundant number, since it is smaller than the sum of its proper divisors (111639258).

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

81868446 is a wasteful number, since it uses less digits than its factorization.

81868446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413496 (or 413493 counting only the distinct ones).

The product of its digits is 294912, while the sum is 45.

The square root of 81868446 is about 9048.1183679260. The cubic root of 81868446 is about 434.2156933612.

The spelling of 81868446 in words is "eighty-one million, eight hundred sixty-eight thousand, four hundred forty-six".