81786446 has 12 divisors (see below), whose sum is σ = 140263368. Its totient is φ = 35036832.

The previous prime is 81786443. The next prime is 81786451. The reversal of 81786446 is 64468718.

It is a junction number, because it is equal to n+sod(n) for n = 81786397 and 81786406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81786443) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 32630 + ... + 35046.

It is an arithmetic number, because the mean of its divisors is an integer number (11688614).

Almost surely, 2^81786446 is an apocalyptic number.

81786446 is a deficient number, since it is larger than the sum of its proper divisors (58476922).

81786446 is an frugal number, since it uses more digits than its factorization.

81786446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4843 (or 2426 counting only the distinct ones).

The product of its digits is 258048, while the sum is 44.

The square root of 81786446 is about 9043.5859038326. The cubic root of 81786446 is about 434.0706737887.

The spelling of 81786446 in words is "eighty-one million, seven hundred eighty-six thousand, four hundred forty-six".