166521013 has 8 divisors (see below), whose sum is σ = 167666688. Its totient is φ = 165379344.

The previous prime is 166521007. The next prime is 166521029. The reversal of 166521013 is 310125661.

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

It is a cyclic number.

It is not a de Polignac number, because 166521013 - 2¹⁷ = 166389941 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 (166521083) 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, 150420 + ... + 151522.

It is an arithmetic number, because the mean of its divisors is an integer number (20958336).

Almost surely, 2^166521013 is an apocalyptic number.

It is an amenable number.

166521013 is a deficient number, since it is larger than the sum of its proper divisors (1145675).

166521013 is a wasteful number, since it uses less digits than its factorization.

166521013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2003.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 166521013 is about 12904.3021120865. The cubic root of 166521013 is about 550.1608488226.

Adding to 166521013 its reverse (310125661), we get a palindrome (476646674).

The spelling of 166521013 in words is "one hundred sixty-six million, five hundred twenty-one thousand, thirteen".