21000201212 has 12 divisors (see below), whose sum is σ = 38684581320. Its totient is φ = 9947463696.

The previous prime is 21000201199. The next prime is 21000201217. The reversal of 21000201212 is 21210200012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21000201193 and 21000201202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000201217) 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, 138159143 + ... + 138159294.

It is an arithmetic number, because the mean of its divisors is an integer number (3223715110).

Almost surely, 2^21000201212 is an apocalyptic number.

It is an amenable number.

21000201212 is a deficient number, since it is larger than the sum of its proper divisors (17684380108).

21000201212 is a wasteful number, since it uses less digits than its factorization.

21000201212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276318460 (or 276318458 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21000201212 its reverse (21210200012), we get a palindrome (42210401224).

The spelling of 21000201212 in words is "twenty-one billion, two hundred one thousand, two hundred twelve".