166040581 has 16 divisors (see below), whose sum is σ = 201350016. Its totient is φ = 133664256.

The previous prime is 166040569. The next prime is 166040591. The reversal of 166040581 is 185040661.

It is a cyclic number.

It is not a de Polignac number, because 166040581 - 2¹¹ = 166038533 is a prime.

It is a super-2 number, since 2×166040581² = 55138949077635122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166040521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68665 + ... + 71041.

It is an arithmetic number, because the mean of its divisors is an integer number (12584376).

Almost surely, 2^166040581 is an apocalyptic number.

It is an amenable number.

166040581 is a deficient number, since it is larger than the sum of its proper divisors (35309435).

166040581 is a wasteful number, since it uses less digits than its factorization.

166040581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2988.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 166040581 is about 12885.6734787127. The cubic root of 166040581 is about 549.6312470360.

The spelling of 166040581 in words is "one hundred sixty-six million, forty thousand, five hundred eighty-one".