81864336 has 40 divisors (see below), whose sum is σ = 213870240. Its totient is φ = 26980096.

The previous prime is 81864301. The next prime is 81864347. The reversal of 81864336 is 63346818.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81864294 and 81864303.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5310 + ... + 13853.

It is an arithmetic number, because the mean of its divisors is an integer number (5346756).

Almost surely, 2^81864336 is an apocalyptic number.

It is an amenable number.

81864336 is an abundant number, since it is smaller than the sum of its proper divisors (132005904).

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

81864336 is a wasteful number, since it uses less digits than its factorization.

81864336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19263 (or 19257 counting only the distinct ones).

The product of its digits is 82944, while the sum is 39.

The square root of 81864336 is about 9047.8912460308. The cubic root of 81864336 is about 434.2084270029.

The spelling of 81864336 in words is "eighty-one million, eight hundred sixty-four thousand, three hundred thirty-six".