121200001021 has 6 divisors (see below), whose sum is σ = 133219835966. Its totient is φ = 110181819000.

The previous prime is 121200001019. The next prime is 121200001033. The reversal of 121200001021 is 120100002121.

It can be written as a sum of positive squares in only one way, i.e., 100021020121 + 21178980900 = 316261^2 + 145530^2 .

It is not a de Polignac number, because 121200001021 - 2¹ = 121200001019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121200000989 and 121200001007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121200001001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 500826330 + ... + 500826571.

Almost surely, 2^121200001021 is an apocalyptic number.

121200001021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121200001021 is a deficient number, since it is larger than the sum of its proper divisors (12019834945).

121200001021 is a wasteful number, since it uses less digits than its factorization.

121200001021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001652923 (or 1001652912 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 121200001021 its reverse (120100002121), we get a palindrome (241300003142).

The spelling of 121200001021 in words is "one hundred twenty-one billion, two hundred million, one thousand, twenty-one".