81347596512 has 768 divisors, whose sum is σ = 296528117760. Its totient is φ = 18895306752.

The previous prime is 81347596487. The next prime is 81347596513. The reversal of 81347596512 is 21569574318.

It is a super-2 number, since 2×81347596512² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81347596513) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 358359343 + ... + 358359569.

It is an arithmetic number, because the mean of its divisors is an integer number (386104320).

Almost surely, 2^81347596512 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 81347596512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148264058880).

81347596512 is an abundant number, since it is smaller than the sum of its proper divisors (215180521248).

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

81347596512 is a wasteful number, since it uses less digits than its factorization.

81347596512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 423 (or 415 counting only the distinct ones).

The product of its digits is 1814400, while the sum is 51.

The spelling of 81347596512 in words is "eighty-one billion, three hundred forty-seven million, five hundred ninety-six thousand, five hundred twelve".