81738572804 has 48 divisors (see below), whose sum is σ = 169320170880. Its totient is φ = 33781681920.

The previous prime is 81738572791. The next prime is 81738572827. The reversal of 81738572804 is 40827583718.

It is a super-3 number, since 3×81738572804³ (a number of 34 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

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, 610664 + ... + 732384.

It is an arithmetic number, because the mean of its divisors is an integer number (3527503560).

Almost surely, 2^81738572804 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 81738572804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84660085440).

81738572804 is an abundant number, since it is smaller than the sum of its proper divisors (87581598076).

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

81738572804 is a wasteful number, since it uses less digits than its factorization.

81738572804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122588 (or 122586 counting only the distinct ones).

The product of its (nonzero) digits is 3010560, while the sum is 53.

The spelling of 81738572804 in words is "eighty-one billion, seven hundred thirty-eight million, five hundred seventy-two thousand, eight hundred four".