81012022121 has 8 divisors (see below), whose sum is σ = 81359280000. Its totient is φ = 80665120080.

The previous prime is 81012022079. The next prime is 81012022123. The reversal of 81012022121 is 12122021018.

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 81012022121 - 2¹⁸ = 81011759977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81012022093 and 81012022102.

It is not an unprimeable number, because it can be changed into a prime (81012022123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 372455 + ... + 548403.

It is an arithmetic number, because the mean of its divisors is an integer number (10169910000).

Almost surely, 2^81012022121 is an apocalyptic number.

It is an amenable number.

81012022121 is a deficient number, since it is larger than the sum of its proper divisors (347257879).

81012022121 is a wasteful number, since it uses less digits than its factorization.

81012022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177919.

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

Adding to 81012022121 its reverse (12122021018), we get a palindrome (93134043139).

The spelling of 81012022121 in words is "eighty-one billion, twelve million, twenty-two thousand, one hundred twenty-one".