81996895201 has 9 divisors (see below), whose sum is σ = 88793568531. Its totient is φ = 75686005512.

The previous prime is 81996895187. The next prime is 81996895241. The reversal of 81996895201 is 10259869918.

The square root of 81996895201 is 286351.

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., 12129718225 + 69867176976 = 110135^2 + 264324^2 .

It is not a de Polignac number, because 81996895201 - 2²¹ = 81994798049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81996895241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3711550 + ... + 3733576.

It is an arithmetic number, because the mean of its divisors is an integer number (9865952059).

Almost surely, 2^81996895201 is an apocalyptic number.

81996895201 is the 286351-st square number.

81996895201 is the 143176-th centered octagonal number.

It is an amenable number.

81996895201 is a deficient number, since it is larger than the sum of its proper divisors (6796673330).

81996895201 is an frugal number, since it uses more digits than its factorization.

81996895201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44080 (or 22040 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 58.

The spelling of 81996895201 in words is "eighty-one billion, nine hundred ninety-six million, eight hundred ninety-five thousand, two hundred one".