21201121212210 has 96 divisors (see below), whose sum is σ = 56002036027392. Its totient is φ = 5564136470400.

The previous prime is 21201121212197. The next prime is 21201121212217. The reversal of 21201121212210 is 1221212110212.

21201121212210 is a `hidden beast` number, since 2 + 120 + 1 + 121 + 212 + 210 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21201121212217) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5465074 + ... + 8501133.

It is an arithmetic number, because the mean of its divisors is an integer number (583354541952).

Almost surely, 2^{21201121212210} is an apocalyptic number.

21201121212210 is an abundant number, since it is smaller than the sum of its proper divisors (34800914815182).

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

21201121212210 is a wasteful number, since it uses less digits than its factorization.

21201121212210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13966488 (or 13966485 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21201121212210 its reverse (1221212110212), we get a palindrome (22422333322422).

The spelling of 21201121212210 in words is "twenty-one trillion, two hundred one billion, one hundred twenty-one million, two hundred twelve thousand, two hundred ten".