81418569516 has 72 divisors (see below), whose sum is σ = 208619174400. Its totient is φ = 26769506400.

The previous prime is 81418569499. The next prime is 81418569517. The reversal of 81418569516 is 61596581418.

81418569516 is a `hidden beast` number, since 8 + 1 + 41 + 85 + 6 + 9 + 516 = 666.

It is not an unprimeable number, because it can be changed into a prime (81418569517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2975425 + ... + 3002663.

Almost surely, 2^81418569516 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 81418569516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104309587200).

81418569516 is an abundant number, since it is smaller than the sum of its proper divisors (127200604884).

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

81418569516 is a wasteful number, since it uses less digits than its factorization.

81418569516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28379 (or 28374 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 54.

The spelling of 81418569516 in words is "eighty-one billion, four hundred eighteen million, five hundred sixty-nine thousand, five hundred sixteen".