81535375936 has 63 divisors (see below), whose sum is σ = 188249478339. Its totient is φ = 34936879488.

The previous prime is 81535375921. The next prime is 81535375937. The reversal of 81535375936 is 63957353518.

The square root of 81535375936 is 285544.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81535375937) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 15987915 + ... + 15993013.

Almost surely, 2^81535375936 is an apocalyptic number.

81535375936 is the 285544-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81535375936

81535375936 is an abundant number, since it is smaller than the sum of its proper divisors (106714102403).

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

81535375936 is an frugal number, since it uses more digits than its factorization.

81535375936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10224 (or 5108 counting only the distinct ones).

The product of its digits is 10206000, while the sum is 55.

The spelling of 81535375936 in words is "eighty-one billion, five hundred thirty-five million, three hundred seventy-five thousand, nine hundred thirty-six".