121221100081 has 12 divisors (see below), whose sum is σ = 127951585092. Its totient is φ = 114827906304.

The previous prime is 121221100069. The next prime is 121221100109. The reversal of 121221100081 is 180001122121.

It can be written as a sum of positive squares in 2 ways, for example, as 111683624481 + 9537475600 = 334191^2 + 97660^2 .

It is not a de Polignac number, because 121221100081 - 2¹⁹ = 121220575793 is a prime.

It is a super-2 number, since 2×121221100081² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121221140081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4845501 + ... + 4870453.

It is an arithmetic number, because the mean of its divisors is an integer number (10662632091).

Almost surely, 2^121221100081 is an apocalyptic number.

It is an amenable number.

121221100081 is a deficient number, since it is larger than the sum of its proper divisors (6730485011).

121221100081 is a wasteful number, since it uses less digits than its factorization.

121221100081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38448 (or 38429 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

The spelling of 121221100081 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred thousand, eighty-one".