81617022597796 has 135 divisors (see below), whose sum is σ = 170593667888049. Its totient is φ = 34067370530592.

The previous prime is 81617022597673. The next prime is 81617022597937. The reversal of 81617022597796 is 69779522071618.

The square root of 81617022597796 is 9034214.

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., 59906268727396 + 21710753870400 = 7739914^2 + 4659480^2 .

It is a super-2 number, since 2×81617022597796² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 233859663430 + ... + 233859663778.

Almost surely, 2^{81617022597796} is an apocalyptic number.

81617022597796 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

81617022597796 is the 9034214-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81617022597796

81617022597796 is an abundant number, since it is smaller than the sum of its proper divisors (88976645290253).

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

81617022597796 is an frugal number, since it uses more digits than its factorization.

81617022597796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 160030080, while the sum is 70.

The spelling of 81617022597796 in words is "eighty-one trillion, six hundred seventeen billion, twenty-two million, five hundred ninety-seven thousand, seven hundred ninety-six".