81396728366 has 8 divisors (see below), whose sum is σ = 122109026520. Its totient is φ = 40693719528.

The previous prime is 81396728363. The next prime is 81396728389. The reversal of 81396728366 is 66382769318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81396728363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2300381 + ... + 2335496.

It is an arithmetic number, because the mean of its divisors is an integer number (15263628315).

Almost surely, 2^81396728366 is an apocalyptic number.

81396728366 is a deficient number, since it is larger than the sum of its proper divisors (40712298154).

81396728366 is a wasteful number, since it uses less digits than its factorization.

81396728366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4644658.

The product of its digits is 15676416, while the sum is 59.

The spelling of 81396728366 in words is "eighty-one billion, three hundred ninety-six million, seven hundred twenty-eight thousand, three hundred sixty-six".