166621113 has 12 divisors (see below), whose sum is σ = 243972820. Its totient is φ = 109558656.

The previous prime is 166621111. The next prime is 166621121. The reversal of 166621113 is 311126661.

It can be written as a sum of positive squares in 2 ways, for example, as 79067664 + 87553449 = 8892^2 + 9357^2 .

It is not a de Polignac number, because 166621113 - 2¹ = 166621111 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166621111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 126148 + ... + 127461.

Almost surely, 2^166621113 is an apocalyptic number.

It is an amenable number.

166621113 is a deficient number, since it is larger than the sum of its proper divisors (77351707).

166621113 is a wasteful number, since it uses less digits than its factorization.

166621113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253688 (or 253685 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 166621113 is about 12908.1800808635. The cubic root of 166621113 is about 550.2710652827.

Adding to 166621113 its reverse (311126661), we get a palindrome (477747774).

The spelling of 166621113 in words is "one hundred sixty-six million, six hundred twenty-one thousand, one hundred thirteen".