1211222000 has 80 divisors (see below), whose sum is σ = 3000370464. Its totient is φ = 472640000.

The previous prime is 1211221993. The next prime is 1211222003. The reversal of 1211222000 is 2221121.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211222003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74615 + ... + 89385.

Almost surely, 2^1211222000 is an apocalyptic number.

1211222000 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 1211222000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1500185232).

1211222000 is an abundant number, since it is smaller than the sum of its proper divisors (1789148464).

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

1211222000 is a wasteful number, since it uses less digits than its factorization.

1211222000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14835 (or 14819 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1211222000 is about 34802.6148442901. The cubic root of 1211222000 is about 1065.9608394716.

Adding to 1211222000 its reverse (2221121), we get a palindrome (1213443121).

The spelling of 1211222000 in words is "one billion, two hundred eleven million, two hundred twenty-two thousand".