81140092201 has 9 divisors (see below), whose sum is σ = 94389773751. Its totient is φ = 69546941352.

The previous prime is 81140092193. The next prime is 81140092207. The reversal of 81140092201 is 10229004118.

The square root of 81140092201 is 284851.

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., 31999843225 + 49140248976 = 178885^2 + 221676^2 .

It is not a de Polignac number, because 81140092201 - 2³ = 81140092193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81140092201.

It is not an unprimeable number, because it can be changed into a prime (81140092207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1973611 + ... + 2014303.

It is an arithmetic number, because the mean of its divisors is an integer number (10487752639).

Almost surely, 2^81140092201 is an apocalyptic number.

81140092201 is the 284851-st square number.

81140092201 is the 142426-th centered octagonal number.

It is an amenable number.

81140092201 is a deficient number, since it is larger than the sum of its proper divisors (13249681550).

81140092201 is an frugal number, since it uses more digits than its factorization.

81140092201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81400 (or 40700 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

Adding to 81140092201 its reverse (10229004118), we get a palindrome (91369096319).

The spelling of 81140092201 in words is "eighty-one billion, one hundred forty million, ninety-two thousand, two hundred one".