81000099000001 has 16 divisors (see below), whose sum is σ = 85375553754960. Its totient is φ = 76730180567040.

The previous prime is 81000098999999. The next prime is 81000099000043. The reversal of 81000099000001 is 10000099000018.

It can be written as a sum of positive squares in 8 ways, for example, as 2132911281601 + 78867187718400 = 1460449^2 + 8880720^2 .

It is a cyclic number.

It is not a de Polignac number, because 81000099000001 - 2¹ = 81000098999999 is a prime.

It is a super-2 number, since 2×81000099000001² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81000099000061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106153921 + ... + 106914241.

It is an arithmetic number, because the mean of its divisors is an integer number (5335972109685).

Almost surely, 2^{81000099000001} is an apocalyptic number.

It is an amenable number.

81000099000001 is a deficient number, since it is larger than the sum of its proper divisors (4375454754959).

81000099000001 is a wasteful number, since it uses less digits than its factorization.

81000099000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 829716.

The product of its (nonzero) digits is 648, while the sum is 28.

The spelling of 81000099000001 in words is "eighty-one trillion, ninety-nine million, one", and thus it is an aban number and an uban number.