166405013 has 4 divisors (see below), whose sum is σ = 166430880. Its totient is φ = 166379148.

The previous prime is 166405003. The next prime is 166405073. The reversal of 166405013 is 310504661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 310504661 = 571 ⋅543791.

It is a cyclic number.

It is not a de Polignac number, because 166405013 - 2⁶ = 166404949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166405003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5078 + ... + 18936.

It is an arithmetic number, because the mean of its divisors is an integer number (41607720).

Almost surely, 2^166405013 is an apocalyptic number.

It is an amenable number.

166405013 is a deficient number, since it is larger than the sum of its proper divisors (25867).

166405013 is a wasteful number, since it uses less digits than its factorization.

166405013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25866.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 166405013 is about 12899.8067039782. The cubic root of 166405013 is about 550.0330701878.

Adding to 166405013 its reverse (310504661), we get a palindrome (476909674).

The spelling of 166405013 in words is "one hundred sixty-six million, four hundred five thousand, thirteen".