221020121210 has 64 divisors (see below), whose sum is σ = 470484875520. Its totient is φ = 73144028160.

The previous prime is 221020121177. The next prime is 221020121219. The reversal of 221020121210 is 12121020122.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221020121219) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7966082 + ... + 7993778.

It is an arithmetic number, because the mean of its divisors is an integer number (7351326180).

Almost surely, 2^221020121210 is an apocalyptic number.

221020121210 is an abundant number, since it is smaller than the sum of its proper divisors (249464754310).

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

221020121210 is a wasteful number, since it uses less digits than its factorization.

221020121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31671.

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

Adding to 221020121210 its reverse (12121020122), we get a palindrome (233141141332).

The spelling of 221020121210 in words is "two hundred twenty-one billion, twenty million, one hundred twenty-one thousand, two hundred ten".