81018974453784 has 32 divisors (see below), whose sum is σ = 202548742728000. Its totient is φ = 27006150605472.

The previous prime is 81018974453783. The next prime is 81018974453803. The reversal of 81018974453784 is 48735447981018.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81018974453783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7062874 + ... + 14557545.

It is an arithmetic number, because the mean of its divisors is an integer number (6329648210250).

Almost surely, 2^{81018974453784} is an apocalyptic number.

It is an amenable number.

81018974453784 is an abundant number, since it is smaller than the sum of its proper divisors (121529768274216).

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

81018974453784 is a wasteful number, since it uses less digits than its factorization.

81018974453784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21776567 (or 21776563 counting only the distinct ones).

The product of its (nonzero) digits is 216760320, while the sum is 69.

The spelling of 81018974453784 in words is "eighty-one trillion, eighteen billion, nine hundred seventy-four million, four hundred fifty-three thousand, seven hundred eighty-four".