16505857 has 4 divisors (see below), whose sum is σ = 17038336. Its totient is φ = 15973380.

The previous prime is 16505837. The next prime is 16505911. The reversal of 16505857 is 75850561.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16505857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16505837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266193 + ... + 266254.

It is an arithmetic number, because the mean of its divisors is an integer number (4259584).

Almost surely, 2^16505857 is an apocalyptic number.

It is an amenable number.

16505857 is a deficient number, since it is larger than the sum of its proper divisors (532479).

16505857 is an equidigital number, since it uses as much as digits as its factorization.

16505857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 532478.

The product of its (nonzero) digits is 42000, while the sum is 37.

The square root of 16505857 is about 4062.7400852134. The cubic root of 16505857 is about 254.6122879045.

The spelling of 16505857 in words is "sixteen million, five hundred five thousand, eight hundred fifty-seven".