1211166513 has 40 divisors (see below), whose sum is σ = 1919819880. Its totient is φ = 758315520.

The previous prime is 1211166511. The next prime is 1211166569. The reversal of 1211166513 is 3156611121.

1211166513 is a `hidden beast` number, since 1 + 2 + 1 + 1 + 1 + 6 + 651 + 3 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 454201344 + 756965169 = 21312^2 + 27513^2 .

It is not a de Polignac number, because 1211166513 - 2¹ = 1211166511 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1211166511) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1141003 + ... + 1142063.

It is an arithmetic number, because the mean of its divisors is an integer number (47995497).

Almost surely, 2^1211166513 is an apocalyptic number.

It is an amenable number.

1211166513 is a deficient number, since it is larger than the sum of its proper divisors (708653367).

1211166513 is a wasteful number, since it uses less digits than its factorization.

1211166513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919 (or 1910 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 1211166513 is about 34801.8176680472. The cubic root of 1211166513 is about 1065.9445617311.

Adding to 1211166513 its reverse (3156611121), we get a palindrome (4367777634).

The spelling of 1211166513 in words is "one billion, two hundred eleven million, one hundred sixty-six thousand, five hundred thirteen".