121221202021 has 8 divisors (see below), whose sum is σ = 126642843000. Its totient is φ = 115882334400.

The previous prime is 121221201991. The next prime is 121221202043. The reversal of 121221202021 is 120202122121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11983680900 + 109237521121 = 109470^2 + 330511^2 .

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 121221202021 - 2¹⁵ = 121221169253 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221201986 and 121221202004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221202061) 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, 20690346 + ... + 20696203.

It is an arithmetic number, because the mean of its divisors is an integer number (15830355375).

Almost surely, 2^121221202021 is an apocalyptic number.

It is an amenable number.

121221202021 is a deficient number, since it is larger than the sum of its proper divisors (5421640979).

121221202021 is a wasteful number, since it uses less digits than its factorization.

121221202021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41386679.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 121221202021 its reverse (120202122121), we get a palindrome (241423324142).

The spelling of 121221202021 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred two thousand, twenty-one".