81384169824 has 48 divisors (see below), whose sum is σ = 237370497840. Its totient is φ = 27128056320.

The previous prime is 81384169799. The next prime is 81384169837. The reversal of 81384169824 is 42896148318.

It is a happy number.

81384169824 is a `hidden beast` number, since 8 + 138 + 416 + 98 + 2 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47096457 + ... + 47098184.

It is an arithmetic number, because the mean of its divisors is an integer number (4945218705).

Almost surely, 2^81384169824 is an apocalyptic number.

It is an amenable number.

81384169824 is an abundant number, since it is smaller than the sum of its proper divisors (155986328016).

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

81384169824 is a wasteful number, since it uses less digits than its factorization.

81384169824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94194660 (or 94194646 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 54.

The spelling of 81384169824 in words is "eighty-one billion, three hundred eighty-four million, one hundred sixty-nine thousand, eight hundred twenty-four".