20571020 has 36 divisors (see below), whose sum is σ = 45902640. Its totient is φ = 7742208.

The previous prime is 20571017. The next prime is 20571041. The reversal of 20571020 is 2017502.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 20571020.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 4001 + ... + 7559.

Almost surely, 2^20571020 is an apocalyptic number.

20571020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20571020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22951320).

20571020 is an abundant number, since it is smaller than the sum of its proper divisors (25331620).

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

20571020 is a wasteful number, since it uses less digits than its factorization.

20571020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3602 (or 3583 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 20571020 is about 4535.5286351207. The cubic root of 20571020 is about 274.0008702265. Note that the first 3 decimals are identical.

Adding to 20571020 its reverse (2017502), we get a palindrome (22588522).

The spelling of 20571020 in words is "twenty million, five hundred seventy-one thousand, twenty".