81105598464 has 192 divisors, whose sum is σ = 246146584320. Its totient is φ = 23508418560.

The previous prime is 81105598447. The next prime is 81105598481. The reversal of 81105598464 is 46489550118.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81105598447) and next prime (81105598481).

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1528344 + ... + 1580520.

It is an arithmetic number, because the mean of its divisors is an integer number (1282013460).

Almost surely, 2^81105598464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81105598464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123073292160).

81105598464 is an abundant number, since it is smaller than the sum of its proper divisors (165040985856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81105598464 is a wasteful number, since it uses less digits than its factorization.

81105598464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52236 (or 52216 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 51.

The spelling of 81105598464 in words is "eighty-one billion, one hundred five million, five hundred ninety-eight thousand, four hundred sixty-four".