81329963 has 16 divisors (see below), whose sum is σ = 95963616. Its totient is φ = 67952640.

The previous prime is 81329939. The next prime is 81329971. The reversal of 81329963 is 36992318.

It is a cyclic number.

It is not a de Polignac number, because 81329963 - 2¹⁰ = 81328939 is a prime.

It is a super-2 number, since 2×81329963² = 13229125763162738, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81329963.

It is not an unprimeable number, because it can be changed into a prime (81329923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35645 + ... + 37857.

It is an arithmetic number, because the mean of its divisors is an integer number (5997726).

Almost surely, 2^81329963 is an apocalyptic number.

81329963 is a deficient number, since it is larger than the sum of its proper divisors (14633653).

81329963 is a wasteful number, since it uses less digits than its factorization.

81329963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2494.

The product of its digits is 69984, while the sum is 41.

The square root of 81329963 is about 9018.3126470532. The cubic root of 81329963 is about 433.2615923970.

The spelling of 81329963 in words is "eighty-one million, three hundred twenty-nine thousand, nine hundred sixty-three".