21212012210 has 16 divisors (see below), whose sum is σ = 38201976000. Its totient is φ = 8480281776.

The previous prime is 21212012149. The next prime is 21212012219. The reversal of 21212012210 is 1221021212.

It is not an unprimeable number, because it can be changed into a prime (21212012219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 545660 + ... + 583239.

It is an arithmetic number, because the mean of its divisors is an integer number (2387623500).

Almost surely, 2^21212012210 is an apocalyptic number.

21212012210 is a deficient number, since it is larger than the sum of its proper divisors (16989963790).

21212012210 is a wasteful number, since it uses less digits than its factorization.

21212012210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1130785.

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

Adding to 21212012210 its reverse (1221021212), we get a palindrome (22433033422).

The spelling of 21212012210 in words is "twenty-one billion, two hundred twelve million, twelve thousand, two hundred ten".