1210021221 has 4 divisors (see below), whose sum is σ = 1613361632. Its totient is φ = 806680812.

The previous prime is 1210021207. The next prime is 1210021243. The reversal of 1210021221 is 1221200121.

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 1210021221 - 2⁷ = 1210021093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210021197 and 1210021206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210021321) 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, 201670201 + ... + 201670206.

It is an arithmetic number, because the mean of its divisors is an integer number (403340408).

Almost surely, 2^1210021221 is an apocalyptic number.

It is an amenable number.

1210021221 is a deficient number, since it is larger than the sum of its proper divisors (403340411).

1210021221 is an equidigital number, since it uses as much as digits as its factorization.

1210021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403340410.

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

The square root of 1210021221 is about 34785.3592909431. The cubic root of 1210021221 is about 1065.6084662467.

Adding to 1210021221 its reverse (1221200121), we get a palindrome (2431221342).

The spelling of 1210021221 in words is "one billion, two hundred ten million, twenty-one thousand, two hundred twenty-one".