1210101221 has 4 divisors (see below), whose sum is σ = 1382972832. Its totient is φ = 1037229612.

The previous prime is 1210101163. The next prime is 1210101229. The reversal of 1210101221 is 1221010121.

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: 1221010121 = 7639 ⋅159839.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1210101221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210101229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86435795 + ... + 86435808.

It is an arithmetic number, because the mean of its divisors is an integer number (345743208).

Almost surely, 2^1210101221 is an apocalyptic number.

It is an amenable number.

1210101221 is a deficient number, since it is larger than the sum of its proper divisors (172871611).

1210101221 is an equidigital number, since it uses as much as digits as its factorization.

1210101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172871610.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1210101221 is about 34786.5091810029. The cubic root of 1210101221 is about 1065.6319498015.

Adding to 1210101221 its reverse (1221010121), we get a palindrome (2431111342).

The spelling of 1210101221 in words is "one billion, two hundred ten million, one hundred one thousand, two hundred twenty-one".