1211220000 has 240 divisors, whose sum is σ = 4416461280. Its totient is φ = 322848000.

The previous prime is 1211219987. The next prime is 1211220011. The reversal of 1211220000 is 221121.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 538879 + ... + 541121.

It is an arithmetic number, because the mean of its divisors is an integer number (18401922).

Almost surely, 2^1211220000 is an apocalyptic number.

1211220000 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 1211220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2208230640).

1211220000 is an abundant number, since it is smaller than the sum of its proper divisors (3205241280).

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

1211220000 is an equidigital number, since it uses as much as digits as its factorization.

1211220000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2282 (or 2253 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1211220000 is about 34802.5861108050. The cubic root of 1211220000 is about 1065.9602527576.

Adding to 1211220000 its reverse (221121), we get a palindrome (1211441121).

The spelling of 1211220000 in words is "one billion, two hundred eleven million, two hundred twenty thousand".