1213011220 has 12 divisors (see below), whose sum is σ = 2547323604. Its totient is φ = 485204480.

The previous prime is 1213011211. The next prime is 1213011227. The reversal of 1213011220 is 221103121.

It can be written as a sum of positive squares in 2 ways, for example, as 143328784 + 1069682436 = 11972^2 + 32706^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1213011220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213011227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30325261 + ... + 30325300.

It is an arithmetic number, because the mean of its divisors is an integer number (212276967).

Almost surely, 2^1213011220 is an apocalyptic number.

1213011220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213011220 is an abundant number, since it is smaller than the sum of its proper divisors (1334312384).

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

1213011220 is a wasteful number, since it uses less digits than its factorization.

1213011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60650570 (or 60650568 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1213011220 is about 34828.3106107661. The cubic root of 1213011220 is about 1066.4854611890.

Adding to 1213011220 its reverse (221103121), we get a palindrome (1434114341).

The spelling of 1213011220 in words is "one billion, two hundred thirteen million, eleven thousand, two hundred twenty".