21021212210 has 16 divisors (see below), whose sum is σ = 39829665600. Its totient is φ = 7965932976.

The previous prime is 21021212141. The next prime is 21021212221. The reversal of 21021212210 is 1221212012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55318790 + ... + 55319169.

It is an arithmetic number, because the mean of its divisors is an integer number (2489354100).

Almost surely, 2^21021212210 is an apocalyptic number.

21021212210 is a deficient number, since it is larger than the sum of its proper divisors (18808453390).

21021212210 is a wasteful number, since it uses less digits than its factorization.

21021212210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110637985.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21021212210 its reverse (1221212012), we get a palindrome (22242424222).

The spelling of 21021212210 in words is "twenty-one billion, twenty-one million, two hundred twelve thousand, two hundred ten".