16720705 has 8 divisors (see below), whose sum is σ = 20443752. Its totient is φ = 13123968.

The previous prime is 16720699. The next prime is 16720789. The reversal of 16720705 is 50702761.

It can be written as a sum of positive squares in 4 ways, for example, as 106929 + 16613776 = 327^2 + 4076^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 16720705 - 2¹⁷ = 16589633 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 31284 + ... + 31813.

It is an arithmetic number, because the mean of its divisors is an integer number (2555469).

Almost surely, 2^16720705 is an apocalyptic number.

It is an amenable number.

16720705 is a deficient number, since it is larger than the sum of its proper divisors (3723047).

16720705 is an equidigital number, since it uses as much as digits as its factorization.

16720705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63155.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 16720705 is about 4089.0958658364. The cubic root of 16720705 is about 255.7122468668.

The spelling of 16720705 in words is "sixteen million, seven hundred twenty thousand, seven hundred five".