20820570 has 16 divisors (see below), whose sum is σ = 49969440. Its totient is φ = 5552144.

The previous prime is 20820559. The next prime is 20820587. The reversal of 20820570 is 7502802.

It is a super-2 number, since 2×20820570² = 866992270249800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20820570.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 346980 + ... + 347039.

It is an arithmetic number, because the mean of its divisors is an integer number (3123090).

Almost surely, 2^20820570 is an apocalyptic number.

20820570 is an abundant number, since it is smaller than the sum of its proper divisors (29148870).

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

20820570 is a wasteful number, since it uses less digits than its factorization.

20820570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694029.

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 20820570 is about 4562.9562785545. The cubic root of 20820570 is about 275.1044011314.

The spelling of 20820570 in words is "twenty million, eight hundred twenty thousand, five hundred seventy".