16640685 has 12 divisors (see below), whose sum is σ = 28843932. Its totient is φ = 8875008.

The previous prime is 16640681. The next prime is 16640731. The reversal of 16640685 is 58604661.

16640685 is a `hidden beast` number, since 1 + 6 + 640 + 6 + 8 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8328996 + 8311689 = 2886^2 + 2883^2 .

It is not a de Polignac number, because 16640685 - 2² = 16640681 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16640681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 184852 + ... + 184941.

It is an arithmetic number, because the mean of its divisors is an integer number (2403661).

Almost surely, 2^16640685 is an apocalyptic number.

16640685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16640685 is a deficient number, since it is larger than the sum of its proper divisors (12203247).

16640685 is a wasteful number, since it uses less digits than its factorization.

16640685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369804 (or 369801 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 16640685 is about 4079.2995722305. The cubic root of 16640685 is about 255.3036751238.

The spelling of 16640685 in words is "sixteen million, six hundred forty thousand, six hundred eighty-five".