21221001212210 has 64 divisors (see below), whose sum is σ = 39684185210880. Its totient is φ = 8160671500800.

The previous prime is 21221001212197. The next prime is 21221001212251. The reversal of 21221001212210 is 1221210012212.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66594119 + ... + 66912021.

It is an arithmetic number, because the mean of its divisors is an integer number (620065393920).

Almost surely, 2^{21221001212210} is an apocalyptic number.

21221001212210 is a deficient number, since it is larger than the sum of its proper divisors (18463183998670).

21221001212210 is a wasteful number, since it uses less digits than its factorization.

21221001212210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318923.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21221001212210 its reverse (1221210012212), we get a palindrome (22442211224422).

The spelling of 21221001212210 in words is "twenty-one trillion, two hundred twenty-one billion, one million, two hundred twelve thousand, two hundred ten".