81915024463 has 4 divisors (see below), whose sum is σ = 86226341560. Its totient is φ = 77603707368.

The previous prime is 81915024449. The next prime is 81915024481. The reversal of 81915024463 is 36442051918.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36442051918 = 2 ⋅18221025959.

It is a cyclic number.

It is not a de Polignac number, because 81915024463 - 2²¹ = 81912927311 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 (81915004463) 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, 2155658520 + ... + 2155658557.

It is an arithmetic number, because the mean of its divisors is an integer number (21556585390).

Almost surely, 2^81915024463 is an apocalyptic number.

81915024463 is a deficient number, since it is larger than the sum of its proper divisors (4311317097).

81915024463 is a wasteful number, since it uses less digits than its factorization.

81915024463 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4311317096.

The product of its (nonzero) digits is 207360, while the sum is 43.

The spelling of 81915024463 in words is "eighty-one billion, nine hundred fifteen million, twenty-four thousand, four hundred sixty-three".