20250581 has 8 divisors (see below), whose sum is σ = 22398264. Its totient is φ = 18187200.

The previous prime is 20250577. The next prime is 20250647. The reversal of 20250581 is 18505202.

It can be written as a sum of positive squares in 4 ways, for example, as 5924356 + 14326225 = 2434^2 + 3785^2 .

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 20250581 - 2² = 20250577 is a prime.

It is a super-3 number, since 3×20250581³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20250541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20570 + ... + 21531.

It is an arithmetic number, because the mean of its divisors is an integer number (2799783).

Almost surely, 2^20250581 is an apocalyptic number.

It is an amenable number.

20250581 is a deficient number, since it is larger than the sum of its proper divisors (2147683).

20250581 is a wasteful number, since it uses less digits than its factorization.

20250581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42151.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 20250581 is about 4500.0645550925. The cubic root of 20250581 is about 272.5706956828.

Adding to 20250581 its reverse (18505202), we get a palindrome (38755783).

The spelling of 20250581 in words is "twenty million, two hundred fifty thousand, five hundred eighty-one".