221111012121220 has 48 divisors (see below), whose sum is σ = 521792408551680. Its totient is φ = 78091380867456.

The previous prime is 221111012121079. The next prime is 221111012121221. The reversal of 221111012121220 is 22121210111122.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (221111012121221) 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, 18487536840 + ... + 18487548799.

It is an arithmetic number, because the mean of its divisors is an integer number (10870675178160).

Almost surely, 2^{221111012121220} is an apocalyptic number.

221111012121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221111012121220 is an abundant number, since it is smaller than the sum of its proper divisors (300681396430460).

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

221111012121220 is a wasteful number, since it uses less digits than its factorization.

221111012121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36975085684 (or 36975085682 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 221111012121220 its reverse (22121210111122), we get a palindrome (243232222232342).

The spelling of 221111012121220 in words is "two hundred twenty-one trillion, one hundred eleven billion, twelve million, one hundred twenty-one thousand, two hundred twenty".