21221420210 has 32 divisors (see below), whose sum is σ = 38602412352. Its totient is φ = 8399016000.

The previous prime is 21221420191. The next prime is 21221420273. The reversal of 21221420210 is 1202412212.

21221420210 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon 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 15 ways as a sum of consecutive naturals, for example, 901085 + ... + 924335.

It is an arithmetic number, because the mean of its divisors is an integer number (1206325386).

Almost surely, 2^21221420210 is an apocalyptic number.

21221420210 is a deficient number, since it is larger than the sum of its proper divisors (17380992142).

21221420210 is a wasteful number, since it uses less digits than its factorization.

21221420210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24218.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21221420210 its reverse (1202412212), we get a palindrome (22423832422).

The spelling of 21221420210 in words is "twenty-one billion, two hundred twenty-one million, four hundred twenty thousand, two hundred ten".