1211318964 has 18 divisors (see below), whose sum is σ = 3061945250. Its totient is φ = 403772976.

The previous prime is 1211318963. The next prime is 1211318971. The reversal of 1211318964 is 4698131121.

It can be written as a sum of positive squares in only one way, i.e., 1203534864 + 7784100 = 34692^2 + 2790^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 33647749 = 1211318964 / (1 + 2 + 1 + 1 + 3 + 1 + 8 + 9 + 6 + 4).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211318963) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16823839 + ... + 16823910.

Almost surely, 2^1211318964 is an apocalyptic number.

It is an amenable number.

1211318964 is an abundant number, since it is smaller than the sum of its proper divisors (1850626286).

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

1211318964 is a wasteful number, since it uses less digits than its factorization.

1211318964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33647759 (or 33647754 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 1211318964 is about 34804.0078726574. The cubic root of 1211318964 is about 1065.9892837669.

The spelling of 1211318964 in words is "one billion, two hundred eleven million, three hundred eighteen thousand, nine hundred sixty-four".