121200002021 has 6 divisors (see below), whose sum is σ = 140987757510. Its totient is φ = 103885715976.

The previous prime is 121200002017. The next prime is 121200002081. The reversal of 121200002021 is 120200002121.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 115974302500 + 5225699521 = 340550^2 + 72289^2 .

It is not a de Polignac number, because 121200002021 - 2² = 121200002017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121200001993 and 121200002011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121200002081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1236734666 + ... + 1236734763.

It is an arithmetic number, because the mean of its divisors is an integer number (23497959585).

Almost surely, 2^121200002021 is an apocalyptic number.

It is an amenable number.

121200002021 is a deficient number, since it is larger than the sum of its proper divisors (19787755489).

121200002021 is an equidigital number, since it uses as much as digits as its factorization.

121200002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2473469443 (or 2473469436 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 121200002021 its reverse (120200002121), we get a palindrome (241400004142).

The spelling of 121200002021 in words is "one hundred twenty-one billion, two hundred million, two thousand, twenty-one".