201012212121821 has 2 divisors, whose sum is σ = 201012212121822. Its totient is φ = 201012212121820.

The previous prime is 201012212121797. The next prime is 201012212121829. The reversal of 201012212121821 is 128121212210102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182584818636025 + 18427393485796 = 13512395^2 + 4292714^2 .

It is a cyclic number.

It is not a de Polignac number, because 201012212121821 - 2⁶ = 201012212121757 is a prime.

It is a super-2 number, since 2×201012212121821² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201012212121829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100506106060910 + 100506106060911.

It is an arithmetic number, because the mean of its divisors is an integer number (100506106060911).

Almost surely, 2^{201012212121821} is an apocalyptic number.

It is an amenable number.

201012212121821 is a deficient number, since it is larger than the sum of its proper divisors (1).

201012212121821 is an equidigital number, since it uses as much as digits as its factorization.

201012212121821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 26.

Adding to 201012212121821 its reverse (128121212210102), we get a palindrome (329133424331923).

The spelling of 201012212121821 in words is "two hundred one trillion, twelve billion, two hundred twelve million, one hundred twenty-one thousand, eight hundred twenty-one".