221102021220 has 24 divisors (see below), whose sum is σ = 619085659584. Its totient is φ = 58960538976.

The previous prime is 221102021213. The next prime is 221102021227. The reversal of 221102021220 is 22120201122.

It is an interprime number because it is at equal distance from previous prime (221102021213) and next prime (221102021227).

It is a super-2 number, since 2×221102021220² (a number of 23 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 221102021220.

It is not an unprimeable number, because it can be changed into a prime (221102021227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1842516784 + ... + 1842516903.

It is an arithmetic number, because the mean of its divisors is an integer number (25795235816).

Almost surely, 2^221102021220 is an apocalyptic number.

221102021220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221102021220 is an abundant number, since it is smaller than the sum of its proper divisors (397983638364).

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

221102021220 is a wasteful number, since it uses less digits than its factorization.

221102021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3685033699 (or 3685033697 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 221102021220 its reverse (22120201122), we get a palindrome (243222222342).

The spelling of 221102021220 in words is "two hundred twenty-one billion, one hundred two million, twenty-one thousand, two hundred twenty".