1211342220 has 144 divisors (see below), whose sum is σ = 4021774848. Its totient is φ = 292682880.

The previous prime is 1211342213. The next prime is 1211342221. The reversal of 1211342220 is 222431121.

It is a happy number.

It is a super-3 number, since 3×1211342220³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1211342193 and 1211342202.

It is not an unprimeable number, because it can be changed into a prime (1211342221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 725827 + ... + 727493.

It is an arithmetic number, because the mean of its divisors is an integer number (27928992).

Almost surely, 2^1211342220 is an apocalyptic number.

1211342220 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 1211342220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2010887424).

1211342220 is an abundant number, since it is smaller than the sum of its proper divisors (2810432628).

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

1211342220 is a wasteful number, since it uses less digits than its factorization.

1211342220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2060 (or 2055 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 1211342220 is about 34804.3419705071. The cubic root of 1211342220 is about 1065.9961056663.

Adding to 1211342220 its reverse (222431121), we get a palindrome (1433773341).

It can be divided in two parts, 121 and 1342220, that added together give a triangular number (1342341 = T₁₆₃₈).

The spelling of 1211342220 in words is "one billion, two hundred eleven million, three hundred forty-two thousand, two hundred twenty".