21021213030 has 16 divisors (see below), whose sum is σ = 50450911344. Its totient is φ = 5605656800.

The previous prime is 21021213029. The next prime is 21021213067. The reversal of 21021213030 is 3031212012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350353521 + ... + 350353580.

It is an arithmetic number, because the mean of its divisors is an integer number (3153181959).

Almost surely, 2^21021213030 is an apocalyptic number.

21021213030 is an abundant number, since it is smaller than the sum of its proper divisors (29429698314).

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

21021213030 is a wasteful number, since it uses less digits than its factorization.

21021213030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700707111.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21021213030 its reverse (3031212012), we get a palindrome (24052425042).

The spelling of 21021213030 in words is "twenty-one billion, twenty-one million, two hundred thirteen thousand, thirty".