121221312021 has 32 divisors (see below), whose sum is σ = 198418533120. Its totient is φ = 72753449472.

The previous prime is 121221312001. The next prime is 121221312041. The reversal of 121221312021 is 120213122121.

It is an interprime number because it is at equal distance from previous prime (121221312001) and next prime (121221312041).

It is not a de Polignac number, because 121221312021 - 2¹⁵ = 121221279253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121221311985 and 121221312003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221312001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5730720 + ... + 5751833.

It is an arithmetic number, because the mean of its divisors is an integer number (6200579160).

Almost surely, 2^121221312021 is an apocalyptic number.

It is an amenable number.

121221312021 is a deficient number, since it is larger than the sum of its proper divisors (77197221099).

121221312021 is a wasteful number, since it uses less digits than its factorization.

121221312021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11482602 (or 11482596 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 121221312021 its reverse (120213122121), we get a palindrome (241434434142).

The spelling of 121221312021 in words is "one hundred twenty-one billion, two hundred twenty-one million, three hundred twelve thousand, twenty-one".