81995177104 has 45 divisors (see below), whose sum is σ = 168800487961. Its totient is φ = 38576802560.

The previous prime is 81995177093. The next prime is 81995177119. The reversal of 81995177104 is 40177159918.

It is a happy number.

The square root of 81995177104 is 286348.

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., 63837075600 + 18158101504 = 252660^2 + 134752^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 19469559 + ... + 19473769.

Almost surely, 2^81995177104 is an apocalyptic number.

81995177104 is the 286348-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81995177104

81995177104 is an abundant number, since it is smaller than the sum of its proper divisors (86805310857).

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

81995177104 is an frugal number, since it uses more digits than its factorization.

81995177104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8464 (or 4230 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 52.

The spelling of 81995177104 in words is "eighty-one billion, nine hundred ninety-five million, one hundred seventy-seven thousand, one hundred four".