1211966500 has 48 divisors (see below), whose sum is σ = 2674329840. Its totient is φ = 479769600.

The previous prime is 1211966477. The next prime is 1211966537. The reversal of 1211966500 is 56691121.

It can be written as a sum of positive squares in 8 ways, for example, as 86229796 + 1125736704 = 9286^2 + 33552^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36006 + ... + 60994.

It is an arithmetic number, because the mean of its divisors is an integer number (55715205).

Almost surely, 2^1211966500 is an apocalyptic number.

1211966500 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 1211966500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1337164920).

1211966500 is an abundant number, since it is smaller than the sum of its proper divisors (1462363340).

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

1211966500 is a wasteful number, since it uses less digits than its factorization.

1211966500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25105 (or 25093 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 1211966500 is about 34813.3092365549. The cubic root of 1211966500 is about 1066.1791989187.

The spelling of 1211966500 in words is "one billion, two hundred eleven million, nine hundred sixty-six thousand, five hundred".