20730385 has 12 divisors (see below), whose sum is σ = 26938332. Its totient is φ = 15307968.

The previous prime is 20730373. The next prime is 20730407. The reversal of 20730385 is 58303702.

It can be written as a sum of positive squares in 6 ways, for example, as 10387729 + 10342656 = 3223^2 + 3216^2 .

It is not a de Polignac number, because 20730385 - 2⁹ = 20729873 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11422 + ... + 13111.

It is an arithmetic number, because the mean of its divisors is an integer number (2244861).

Almost surely, 2^20730385 is an apocalyptic number.

It is an amenable number.

20730385 is a deficient number, since it is larger than the sum of its proper divisors (6207947).

20730385 is a wasteful number, since it uses less digits than its factorization.

20730385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24564 (or 24551 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 20730385 is about 4553.0632545573. The cubic root of 20730385 is about 274.7066182486.

It can be divided in two parts, 20730 and 385, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 20730385 in words is "twenty million, seven hundred thirty thousand, three hundred eighty-five".