20570 has 24 divisors (see below), whose sum is σ = 43092. Its totient is φ = 7040.

The previous prime is 20563. The next prime is 20593. The reversal of 20570 is 7502.

It can be written as a sum of positive squares in 2 ways, for example, as 20449 + 121 = 143^2 + 11^2 .

20570 is an undulating number in base 13.

It is a Curzon number.

It is a nialpdrome in base 12.

It is a zygodrome in base 4.

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, 1202 + ... + 1218.

2²⁰⁵⁷⁰ is an apocalyptic number.

20570 is an abundant number, since it is smaller than the sum of its proper divisors (22522).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21546).

20570 is a wasteful number, since it uses less digits than its factorization.

20570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 70, while the sum is 14.

The square root of 20570 is about 143.4224529145. The cubic root of 20570 is about 27.3996341436.

The spelling of 20570 in words is "twenty thousand, five hundred seventy".