81396663 has 8 divisors (see below), whose sum is σ = 114913008. Its totient is φ = 51072384.

The previous prime is 81396661. The next prime is 81396671. The reversal of 81396663 is 36669318.

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

It is not a de Polignac number, because 81396663 - 2¹ = 81396661 is a prime.

It is a fibodiv number, since the Fibonacci-like sequence with seeds 81396 and 663 contains 81396663 itself.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81396661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 797956 + ... + 798057.

It is an arithmetic number, because the mean of its divisors is an integer number (14364126).

Almost surely, 2^81396663 is an apocalyptic number.

81396663 is a deficient number, since it is larger than the sum of its proper divisors (33516345).

81396663 is a wasteful number, since it uses less digits than its factorization.

81396663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1596033.

The product of its digits is 139968, while the sum is 42.

The square root of 81396663 is about 9022.0099201896. The cubic root of 81396663 is about 433.3800016142.

The spelling of 81396663 in words is "eighty-one million, three hundred ninety-six thousand, six hundred sixty-three".