121311212021 has 2 divisors, whose sum is σ = 121311212022. Its totient is φ = 121311212020.

The previous prime is 121311211933. The next prime is 121311212083. The reversal of 121311212021 is 120212113121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119377851121 + 1933360900 = 345511^2 + 43970^2 .

It is a cyclic number.

It is not a de Polignac number, because 121311212021 - 2²² = 121307017717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121311212821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60655606010 + 60655606011.

It is an arithmetic number, because the mean of its divisors is an integer number (60655606011).

Almost surely, 2^121311212021 is an apocalyptic number.

It is an amenable number.

121311212021 is a deficient number, since it is larger than the sum of its proper divisors (1).

121311212021 is an equidigital number, since it uses as much as digits as its factorization.

121311212021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 121311212021 its reverse (120212113121), we get a palindrome (241523325142).

The spelling of 121311212021 in words is "one hundred twenty-one billion, three hundred eleven million, two hundred twelve thousand, twenty-one".