81000018000002 has 8 divisors (see below), whose sum is σ = 124463442292812. Its totient is φ = 39512203902400.

The previous prime is 81000017999947. The next prime is 81000018000029. The reversal of 81000018000002 is 20000081000018.

It is a Cunningham number, because it is equal to 9000001²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 81000018000001 + 1 = 9000001^2 + 1^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×81000018000002² (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 3 ways as a sum of consecutive naturals, for example, 493902548699 + ... + 493902548862.

Almost surely, 2^{81000018000002} is an apocalyptic number.

81000018000002 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

81000018000002 is a deficient number, since it is larger than the sum of its proper divisors (43463424292810).

81000018000002 is a wasteful number, since it uses less digits than its factorization.

81000018000002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987805097604.

The product of its (nonzero) digits is 128, while the sum is 20.

The spelling of 81000018000002 in words is "eighty-one trillion, eighteen million, two", and thus it is an aban number and an uban number.