21000203212 has 24 divisors (see below), whose sum is σ = 36830480400. Its totient is φ = 10477237056.

The previous prime is 21000203177. The next prime is 21000203233. The reversal of 21000203212 is 21230200012.

It is a junction number, because it is equal to n+sod(n) for n = 21000203192 and 21000203201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4220358 + ... + 4225330.

It is an arithmetic number, because the mean of its divisors is an integer number (1534603350).

Almost surely, 2^21000203212 is an apocalyptic number.

It is an amenable number.

21000203212 is a deficient number, since it is larger than the sum of its proper divisors (15830277188).

21000203212 is a wasteful number, since it uses less digits than its factorization.

21000203212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7065 (or 7063 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

Adding to 21000203212 its reverse (21230200012), we get a palindrome (42230403224).

The spelling of 21000203212 in words is "twenty-one billion, two hundred three thousand, two hundred twelve".