20730856 has 16 divisors (see below), whose sum is σ = 39256740. Its totient is φ = 10262400.

The previous prime is 20730839. The next prime is 20730869. The reversal of 20730856 is 65803702.

It can be written as a sum of positive squares in 2 ways, for example, as 19980900 + 749956 = 4470^2 + 866^2 .

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 3 ways as a sum of consecutive naturals, for example, 12021 + ... + 13636.

Almost surely, 2^20730856 is an apocalyptic number.

It is an amenable number.

20730856 is a deficient number, since it is larger than the sum of its proper divisors (18525884).

20730856 is a wasteful number, since it uses less digits than its factorization.

20730856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25764 (or 25760 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20730856 is about 4553.1149776829. The cubic root of 20730856 is about 274.7086987026.

The spelling of 20730856 in words is "twenty million, seven hundred thirty thousand, eight hundred fifty-six".