16660557 has 6 divisors (see below), whose sum is σ = 24065262. Its totient is φ = 11107032.

The previous prime is 16660543. The next prime is 16660577. The reversal of 16660557 is 75506661.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 16232841 + 427716 = 4029^2 + 654^2 .

It is not a de Polignac number, because 16660557 - 2¹⁵ = 16627789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16660517) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 925578 + ... + 925595.

It is an arithmetic number, because the mean of its divisors is an integer number (4010877).

Almost surely, 2^16660557 is an apocalyptic number.

It is an amenable number.

16660557 is a deficient number, since it is larger than the sum of its proper divisors (7404705).

16660557 is a wasteful number, since it uses less digits than its factorization.

16660557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1851179 (or 1851176 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 36.

The square root of 16660557 is about 4081.7345577585. The cubic root of 16660557 is about 255.4052610151.

The spelling of 16660557 in words is "sixteen million, six hundred sixty thousand, five hundred fifty-seven".