81000130121 has 4 divisors (see below), whose sum is σ = 81004771200. Its totient is φ = 80995489044.

The previous prime is 81000130097. The next prime is 81000130157. The reversal of 81000130121 is 12103100018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81000130121 - 2²² = 80995935817 is a prime.

It is a super-2 number, since 2×81000130121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81000130121.

It is not an unprimeable number, because it can be changed into a prime (81000130021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2294261 + ... + 2329298.

It is an arithmetic number, because the mean of its divisors is an integer number (20251192800).

Almost surely, 2^81000130121 is an apocalyptic number.

It is an amenable number.

81000130121 is a deficient number, since it is larger than the sum of its proper divisors (4641079).

81000130121 is a wasteful number, since it uses less digits than its factorization.

81000130121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4641078.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 81000130121 its reverse (12103100018), we get a palindrome (93103230139).

The spelling of 81000130121 in words is "eighty-one billion, one hundred thirty thousand, one hundred twenty-one".