1236213220 has 48 divisors (see below), whose sum is σ = 2857171968. Its totient is φ = 445544960.

The previous prime is 1236213203. The next prime is 1236213221. The reversal of 1236213220 is 223126321.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a junction number, because it is equal to n+sod(n) for n = 1236213191 and 1236213200.

It is not an unprimeable number, because it can be changed into a prime (1236213221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4 + ... + 49723.

It is an arithmetic number, because the mean of its divisors is an integer number (59524416).

Almost surely, 2^1236213220 is an apocalyptic number.

1236213220 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 1236213220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1428585984).

1236213220 is an abundant number, since it is smaller than the sum of its proper divisors (1620958748).

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

1236213220 is a wasteful number, since it uses less digits than its factorization.

1236213220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49860 (or 49858 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 1236213220 is about 35159.8239472270. The cubic root of 1236213220 is about 1073.2423326867.

Adding to 1236213220 its reverse (223126321), we get a palindrome (1459339541).

The spelling of 1236213220 in words is "one billion, two hundred thirty-six million, two hundred thirteen thousand, two hundred twenty".