81000099000031 has 8 divisors (see below), whose sum is σ = 82209231441200. Its totient is φ = 79790971727808.

The previous prime is 81000098999999. The next prime is 81000099000043. The reversal of 81000099000031 is 13000099000018.

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

It is a cyclic number.

It is not a de Polignac number, because 81000099000031 - 2⁵ = 81000098999999 is a prime.

It is a super-2 number, since 2×81000099000031² (a number of 29 digits) contains 22 as substring.

It is the 9000006-th Hogben number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81000098999957 and 81000099000002.

It is a congruent number.

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

It is a nontrivial repunit in base 9000005.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40109395 + ... + 42080443.

It is an arithmetic number, because the mean of its divisors is an integer number (10276153930150).

Almost surely, 2^{81000099000031} is an apocalyptic number.

81000099000031 is a deficient number, since it is larger than the sum of its proper divisors (1209132441169).

81000099000031 is a wasteful number, since it uses less digits than its factorization.

81000099000031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2584473.

The product of its (nonzero) digits is 1944, while the sum is 31.

The spelling of 81000099000031 in words is "eighty-one trillion, ninety-nine million, thirty-one", and thus it is an aban number and an uban number.