1213872220 has 48 divisors (see below), whose sum is σ = 2786918400. Its totient is φ = 440448320.

The previous prime is 1213872203. The next prime is 1213872229. The reversal of 1213872220 is 222783121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213872229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99621 + ... + 111139.

It is an arithmetic number, because the mean of its divisors is an integer number (58060800).

Almost surely, 2^1213872220 is an apocalyptic number.

1213872220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1213872220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1393459200).

1213872220 is an abundant number, since it is smaller than the sum of its proper divisors (1573046180).

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

1213872220 is a wasteful number, since it uses less digits than its factorization.

1213872220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12018 (or 12016 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 1213872220 is about 34840.6690521293. The cubic root of 1213872220 is about 1066.7377333293.

The spelling of 1213872220 in words is "one billion, two hundred thirteen million, eight hundred seventy-two thousand, two hundred twenty".