1213211766 has 32 divisors (see below), whose sum is σ = 2766784608. Its totient is φ = 351336960.

The previous prime is 1213211743. The next prime is 1213211767. The reversal of 1213211766 is 6671123121.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213211767) by changing a digit.

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, 456145 + ... + 458796.

It is an arithmetic number, because the mean of its divisors is an integer number (86462019).

Almost surely, 2^1213211766 is an apocalyptic number.

1213211766 is an abundant number, since it is smaller than the sum of its proper divisors (1553572842).

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

1213211766 is a wasteful number, since it uses less digits than its factorization.

1213211766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914976.

The product of its digits is 3024, while the sum is 30.

The square root of 1213211766 is about 34831.1895576364. The cubic root of 1213211766 is about 1066.5442316285.

Adding to 1213211766 its reverse (6671123121), we get a palindrome (7884334887).

The spelling of 1213211766 in words is "one billion, two hundred thirteen million, two hundred eleven thousand, seven hundred sixty-six".