21030321212 has 24 divisors (see below), whose sum is σ = 37454659200. Its totient is φ = 10330406576.

The previous prime is 21030321199. The next prime is 21030321227. The reversal of 21030321212 is 21212303012.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

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, 117512 + ... + 236367.

It is an arithmetic number, because the mean of its divisors is an integer number (1560610800).

Almost surely, 2^21030321212 is an apocalyptic number.

It is an amenable number.

21030321212 is a deficient number, since it is larger than the sum of its proper divisors (16424337988).

21030321212 is a wasteful number, since it uses less digits than its factorization.

21030321212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354145 (or 354143 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21030321212 its reverse (21212303012), we get a palindrome (42242624224).

The spelling of 21030321212 in words is "twenty-one billion, thirty million, three hundred twenty-one thousand, two hundred twelve".