16820645 has 8 divisors (see below), whose sum is σ = 20319360. Its totient is φ = 13366800.

The previous prime is 16820603. The next prime is 16820647. The reversal of 16820645 is 54602861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16820645 - 2¹⁴ = 16804261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16820647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10385 + ... + 11894.

It is an arithmetic number, because the mean of its divisors is an integer number (2539920).

Almost surely, 2^16820645 is an apocalyptic number.

It is an amenable number.

16820645 is a deficient number, since it is larger than the sum of its proper divisors (3498715).

16820645 is a wasteful number, since it uses less digits than its factorization.

16820645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22435.

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 16820645 is about 4101.2979652788. The cubic root of 16820645 is about 256.2207009928.

The spelling of 16820645 in words is "sixteen million, eight hundred twenty thousand, six hundred forty-five".