1661166013 has 8 divisors (see below), whose sum is σ = 1789515000. Its totient is φ = 1532898048.

The previous prime is 1661165977. The next prime is 1661166019. The reversal of 1661166013 is 3106611661.

It can be written as a sum of positive squares in 4 ways, for example, as 201696804 + 1459469209 = 14202^2 + 38203^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661166013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661166019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26313 + ... + 63361.

It is an arithmetic number, because the mean of its divisors is an integer number (223689375).

Almost surely, 2^1661166013 is an apocalyptic number.

1661166013 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1661166013 is a deficient number, since it is larger than the sum of its proper divisors (128348987).

1661166013 is a wasteful number, since it uses less digits than its factorization.

1661166013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40511.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 1661166013 is about 40757.4043947845. The cubic root of 1661166013 is about 1184.3253146920.

Adding to 1661166013 its reverse (3106611661), we get a palindrome (4767777674).

The spelling of 1661166013 in words is "one billion, six hundred sixty-one million, one hundred sixty-six thousand, thirteen".