21021330210 has 32 divisors (see below), whose sum is σ = 50922706752. Its totient is φ = 5553297600.

The previous prime is 21021330203. The next prime is 21021330259. The reversal of 21021330210 is 1203312012.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21021330210.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3271141 + ... + 3277560.

It is an arithmetic number, because the mean of its divisors is an integer number (1591334586).

Almost surely, 2^21021330210 is an apocalyptic number.

21021330210 is an abundant number, since it is smaller than the sum of its proper divisors (29901376542).

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

21021330210 is a wasteful number, since it uses less digits than its factorization.

21021330210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6548818.

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

Adding to 21021330210 its reverse (1203312012), we get a palindrome (22224642222).

The spelling of 21021330210 in words is "twenty-one billion, twenty-one million, three hundred thirty thousand, two hundred ten".