81811463 has 8 divisors (see below), whose sum is σ = 87145632. Its totient is φ = 76535296.

The previous prime is 81811447. The next prime is 81811517. The reversal of 81811463 is 36411818.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81811463 - 2⁴ = 81811447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81811363) 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, 11570 + ... + 17247.

It is an arithmetic number, because the mean of its divisors is an integer number (10893204).

Almost surely, 2^81811463 is an apocalyptic number.

81811463 is a deficient number, since it is larger than the sum of its proper divisors (5334169).

81811463 is a wasteful number, since it uses less digits than its factorization.

81811463 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29001.

The product of its digits is 4608, while the sum is 32.

The square root of 81811463 is about 9044.9689330589. The cubic root of 81811463 is about 434.1149274092.

The spelling of 81811463 in words is "eighty-one million, eight hundred eleven thousand, four hundred sixty-three".