20730857 has 8 divisors (see below), whose sum is σ = 23720256. Its totient is φ = 17748432.

The previous prime is 20730839. The next prime is 20730869. The reversal of 20730857 is 75803702.

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 20730857 - 2²⁰ = 19682281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20730887) 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, 9383 + ... + 11379.

It is an arithmetic number, because the mean of its divisors is an integer number (2965032).

Almost surely, 2^20730857 is an apocalyptic number.

It is an amenable number.

20730857 is a deficient number, since it is larger than the sum of its proper divisors (2989399).

20730857 is a wasteful number, since it uses less digits than its factorization.

20730857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3487.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 20730857 is about 4553.1150874978. The cubic root of 20730857 is about 274.7087031197.

The spelling of 20730857 in words is "twenty million, seven hundred thirty thousand, eight hundred fifty-seven".