21210030012 has 12 divisors (see below), whose sum is σ = 49490070056. Its totient is φ = 7070010000.

The previous prime is 21210029983. The next prime is 21210030013. The reversal of 21210030012 is 21003001212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Harshad number since it is a multiple of its sum of digits (12), and also a Moran number because the ratio is a prime number: 1767502501 = 21210030012 / (2 + 1 + 2 + 1 + 0 + 0 + 3 + 0 + 0 + 1 + 2).

It is a self number, because there is not a number n which added to its sum of digits gives 21210030012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210030013) 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, 883751239 + ... + 883751262.

Almost surely, 2^21210030012 is an apocalyptic number.

It is an amenable number.

21210030012 is an abundant number, since it is smaller than the sum of its proper divisors (28280040044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21210030012 is a wasteful number, since it uses less digits than its factorization.

21210030012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767502508 (or 1767502506 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21210030012 its reverse (21003001212), we get a palindrome (42213031224).

The spelling of 21210030012 in words is "twenty-one billion, two hundred ten million, thirty thousand, twelve".