1211666120 has 96 divisors (see below), whose sum is σ = 3216386880. Its totient is φ = 409530240.

The previous prime is 1211666107. The next prime is 1211666149. The reversal of 1211666120 is 216661121.

It is a self number, because there is not a number n which added to its sum of digits gives 1211666120.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134807 + ... + 143513.

It is an arithmetic number, because the mean of its divisors is an integer number (33504030).

Almost surely, 2^1211666120 is an apocalyptic number.

1211666120 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 1211666120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1608193440).

1211666120 is an abundant number, since it is smaller than the sum of its proper divisors (2004720760).

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

1211666120 is a wasteful number, since it uses less digits than its factorization.

1211666120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8803 (or 8792 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1211666120 is about 34808.9948145591. The cubic root of 1211666120 is about 1066.0911091985.

The spelling of 1211666120 in words is "one billion, two hundred eleven million, six hundred sixty-six thousand, one hundred twenty".