1210220021221 has 16 divisors (see below), whose sum is σ = 1291304177280. Its totient is φ = 1130267335680.

The previous prime is 1210220021189. The next prime is 1210220021237. The reversal of 1210220021221 is 1221200220121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1210220021221 - 2⁵ = 1210220021189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1210220021195 and 1210220021204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210220021261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 708240 + ... + 1709398.

It is an arithmetic number, because the mean of its divisors is an integer number (80706511080).

Almost surely, 2^{1210220021221} is an apocalyptic number.

It is an amenable number.

1210220021221 is a deficient number, since it is larger than the sum of its proper divisors (81084156059).

1210220021221 is a wasteful number, since it uses less digits than its factorization.

1210220021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001724.

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

Adding to 1210220021221 its reverse (1221200220121), we get a palindrome (2431420241342).

The spelling of 1210220021221 in words is "one trillion, two hundred ten billion, two hundred twenty million, twenty-one thousand, two hundred twenty-one".