1212202021 has 4 divisors (see below), whose sum is σ = 1251305344. Its totient is φ = 1173098700.

The previous prime is 1212201997. The next prime is 1212202031. The reversal of 1212202021 is 1202022121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1202022121 = 2617 ⋅459313.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212202021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212201992 and 1212202010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212202031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19551615 + ... + 19551676.

It is an arithmetic number, because the mean of its divisors is an integer number (312826336).

Almost surely, 2^1212202021 is an apocalyptic number.

It is an amenable number.

1212202021 is a deficient number, since it is larger than the sum of its proper divisors (39103323).

1212202021 is an equidigital number, since it uses as much as digits as its factorization.

1212202021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39103322.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1212202021 is about 34816.6917009644. The cubic root of 1212202021 is about 1066.2482578481.

Adding to 1212202021 its reverse (1202022121), we get a palindrome (2414224142).

The spelling of 1212202021 in words is "one billion, two hundred twelve million, two hundred two thousand, twenty-one".