21212210201 has 24 divisors (see below), whose sum is σ = 26623089864. Its totient is φ = 16751992320.

The previous prime is 21212210113. The next prime is 21212210209. The reversal of 21212210201 is 10201221212.

It can be written as a sum of positive squares in 4 ways, for example, as 5058054400 + 16154155801 = 71120^2 + 127099^2 .

It is not a de Polignac number, because 21212210201 - 2¹⁸ = 21211948057 is a prime.

It is a super-2 number, since 2×21212210201² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21212210209) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 313841 + ... + 375393.

It is an arithmetic number, because the mean of its divisors is an integer number (1109295411).

Almost surely, 2^21212210201 is an apocalyptic number.

It is an amenable number.

21212210201 is a deficient number, since it is larger than the sum of its proper divisors (5410879663).

21212210201 is a wasteful number, since it uses less digits than its factorization.

21212210201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62121 (or 62114 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21212210201 its reverse (10201221212), we get a palindrome (31413431413).

The spelling of 21212210201 in words is "twenty-one billion, two hundred twelve million, two hundred ten thousand, two hundred one".