221212121010 has 32 divisors (see below), whose sum is σ = 536382387072. Its totient is φ = 58381754880.

The previous prime is 221212120999. The next prime is 221212121021. The reversal of 221212121010 is 10121212122.

It is an interprime number because it is at equal distance from previous prime (221212120999) and next prime (221212121021).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38006046 + ... + 38011865.

It is an arithmetic number, because the mean of its divisors is an integer number (16761949596).

Almost surely, 2^221212121010 is an apocalyptic number.

221212121010 is an abundant number, since it is smaller than the sum of its proper divisors (315170266062).

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

221212121010 is a wasteful number, since it uses less digits than its factorization.

221212121010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76018018.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 221212121010 its reverse (10121212122), we get a palindrome (231333333132).

The spelling of 221212121010 in words is "two hundred twenty-one billion, two hundred twelve million, one hundred twenty-one thousand, ten".