2102220121 has 4 divisors (see below), whose sum is σ = 2174710500. Its totient is φ = 2029729744.

The previous prime is 2102220061. The next prime is 2102220149. The reversal of 2102220121 is 1210222012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1613146896 + 489073225 = 40164^2 + 22115^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102220121 - 2⁷ = 2102219993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2102220151) 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, 36245146 + ... + 36245203.

It is an arithmetic number, because the mean of its divisors is an integer number (543677625).

Almost surely, 2^2102220121 is an apocalyptic number.

It is an amenable number.

2102220121 is a deficient number, since it is larger than the sum of its proper divisors (72490379).

2102220121 is an equidigital number, since it uses as much as digits as its factorization.

2102220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72490378.

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

The square root of 2102220121 is about 45849.9740566993. The cubic root of 2102220121 is about 1281.0302823520.

Adding to 2102220121 its reverse (1210222012), we get a palindrome (3312442133).

The spelling of 2102220121 in words is "two billion, one hundred two million, two hundred twenty thousand, one hundred twenty-one".