201213121 has 2 divisors, whose sum is σ = 201213122. Its totient is φ = 201213120.

The previous prime is 201213101. The next prime is 201213137. The reversal of 201213121 is 121312102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200081025 + 1132096 = 14145^2 + 1064^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201213121 is a prime.

It is not a weakly prime, because it can be changed into another prime (201213101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100606560 + 100606561.

It is an arithmetic number, because the mean of its divisors is an integer number (100606561).

Almost surely, 2^201213121 is an apocalyptic number.

It is an amenable number.

201213121 is a deficient number, since it is larger than the sum of its proper divisors (1).

201213121 is an equidigital number, since it uses as much as digits as its factorization.

201213121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 201213121 is about 14184.9610856005. The cubic root of 201213121 is about 585.9835607917.

Adding to 201213121 its reverse (121312102), we get a palindrome (322525223).

The spelling of 201213121 in words is "two hundred one million, two hundred thirteen thousand, one hundred twenty-one".