81815463 has 12 divisors (see below), whose sum is σ = 124398040. Its totient is φ = 51672816.

The previous prime is 81815449. The next prime is 81815497. The reversal of 81815463 is 36451818.

It is not a de Polignac number, because 81815463 - 2⁵ = 81815431 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 (81815413) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 239056 + ... + 239397.

Almost surely, 2^81815463 is an apocalyptic number.

81815463 is a deficient number, since it is larger than the sum of its proper divisors (42582577).

81815463 is a wasteful number, since it uses less digits than its factorization.

81815463 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478478 (or 478475 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 81815463 is about 9045.1900477547. The cubic root of 81815463 is about 434.1220023404.

The spelling of 81815463 in words is "eighty-one million, eight hundred fifteen thousand, four hundred sixty-three".