20504261 has 6 divisors (see below), whose sum is σ = 21781650. Its totient is φ = 19297856.

The previous prime is 20504221. The next prime is 20504353. The reversal of 20504261 is 16240502.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 10857025 + 9647236 = 3295^2 + 3106^2 .

It is not a de Polignac number, because 20504261 - 2¹⁴ = 20487877 is a prime.

It is a super-2 number, since 2×20504261² = 840849438312242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20504221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35186 + ... + 35763.

It is an arithmetic number, because the mean of its divisors is an integer number (3630275).

Almost surely, 2^20504261 is an apocalyptic number.

It is an amenable number.

20504261 is a deficient number, since it is larger than the sum of its proper divisors (1277389).

20504261 is an equidigital number, since it uses as much as digits as its factorization.

20504261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70983 (or 70966 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20504261 is about 4528.1630933525. The cubic root of 20504261 is about 273.7041445819.

Adding to 20504261 its reverse (16240502), we get a palindrome (36744763).

The spelling of 20504261 in words is "twenty million, five hundred four thousand, two hundred sixty-one".