21212212212210 has 32 divisors (see below), whose sum is σ = 50910061332672. Its totient is φ = 5656506365120.

The previous prime is 21212212212203. The next prime is 21212212212211. The reversal of 21212212212210 is 1221221221212.

It is not an unprimeable number, because it can be changed into a prime (21212212212211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3144084 + ... + 7232543.

It is an arithmetic number, because the mean of its divisors is an integer number (1590939416646).

Almost surely, 2^{21212212212210} is an apocalyptic number.

21212212212210 is an abundant number, since it is smaller than the sum of its proper divisors (29697849120462).

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

21212212212210 is a wasteful number, since it uses less digits than its factorization.

21212212212210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10444778.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21212212212210 its reverse (1221221221212), we get a palindrome (22433433433422).

The spelling of 21212212212210 in words is "twenty-one trillion, two hundred twelve billion, two hundred twelve million, two hundred twelve thousand, two hundred ten".