16920865 has 16 divisors (see below), whose sum is σ = 23154768. Its totient is φ = 11759616.

The previous prime is 16920859. The next prime is 16920901. The reversal of 16920865 is 56802961.

It can be written as a sum of positive squares in 8 ways, for example, as 3968064 + 12952801 = 1992^2 + 3599^2 .

It is a cyclic number.

It is not a de Polignac number, because 16920865 - 2¹⁵ = 16888097 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6552 + ... + 8761.

It is an arithmetic number, because the mean of its divisors is an integer number (1447173).

Almost surely, 2^16920865 is an apocalyptic number.

It is an amenable number.

16920865 is a deficient number, since it is larger than the sum of its proper divisors (6233903).

16920865 is a wasteful number, since it uses less digits than its factorization.

16920865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15348.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 16920865 is about 4113.4979032449. The cubic root of 16920865 is about 256.7285611867.

The spelling of 16920865 in words is "sixteen million, nine hundred twenty thousand, eight hundred sixty-five".