1212201021 has 4 divisors (see below), whose sum is σ = 1616268032. Its totient is φ = 808134012.

The previous prime is 1212201019. The next prime is 1212201037. The reversal of 1212201021 is 1201022121.

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.

It is not a de Polignac number, because 1212201021 - 2¹ = 1212201019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212200988 and 1212201006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212201041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202033501 + ... + 202033506.

It is an arithmetic number, because the mean of its divisors is an integer number (404067008).

Almost surely, 2^1212201021 is an apocalyptic number.

It is an amenable number.

1212201021 is a deficient number, since it is larger than the sum of its proper divisors (404067011).

1212201021 is an equidigital number, since it uses as much as digits as its factorization.

1212201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404067010.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1212201021 is about 34816.6773400335. The cubic root of 1212201021 is about 1066.2479646493.

Adding to 1212201021 its reverse (1201022121), we get a palindrome (2413223142).

The spelling of 1212201021 in words is "one billion, two hundred twelve million, two hundred one thousand, twenty-one".