1220211220 has 24 divisors (see below), whose sum is σ = 2593319904. Its totient is φ = 482203296.

The previous prime is 1220211211. The next prime is 1220211229. The reversal of 1220211220 is 221120221.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1220211211) and next prime (1220211229).

It is a self number, because there is not a number n which added to its sum of digits gives 1220211220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220211229) 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, 365874 + ... + 369193.

It is an arithmetic number, because the mean of its divisors is an integer number (108054996).

Almost surely, 2^1220211220 is an apocalyptic number.

1220211220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220211220 is an abundant number, since it is smaller than the sum of its proper divisors (1373108684).

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

1220211220 is a wasteful number, since it uses less digits than its factorization.

1220211220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735159 (or 735157 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1220211220 is about 34931.5218677916. The cubic root of 1220211220 is about 1068.5913918499.

Adding to 1220211220 its reverse (221120221), we get a palindrome (1441331441).

Subtracting from 1220211220 its reverse (221120221), we obtain a palindrome (999090999).

The spelling of 1220211220 in words is "one billion, two hundred twenty million, two hundred eleven thousand, two hundred twenty".