81323069584 has 15 divisors (see below), whose sum is σ = 157565657433. Its totient is φ = 40660964448.

The previous prime is 81323069579. The next prime is 81323069647. The reversal of 81323069584 is 48596032318.

The square root of 81323069584 is 285172.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 81304819600 + 18249984 = 285140^2 + 4272^2 .

It is a super-2 number, since 2×81323069584² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1105042 + ... + 1176334.

Almost surely, 2^81323069584 is an apocalyptic number.

81323069584 is the 285172-nd square number.

It is an amenable number.

81323069584 is a deficient number, since it is larger than the sum of its proper divisors (76242587849).

81323069584 is an frugal number, since it uses more digits than its factorization.

81323069584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142594 (or 71295 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 49.

Multiplying 81323069584 by its sum of digits (49), we get a square (3984830409616 = 1996204²).

The spelling of 81323069584 in words is "eighty-one billion, three hundred twenty-three million, sixty-nine thousand, five hundred eighty-four".