20217571525 has 24 divisors (see below), whose sum is σ = 25381355400. Its totient is φ = 15973478400.

The previous prime is 20217571457. The next prime is 20217571529. The reversal of 20217571525 is 52517571202.

It can be written as a sum of positive squares in 12 ways, for example, as 15356414241 + 4861157284 = 123921^2 + 69722^2 .

It is not a de Polignac number, because 20217571525 - 2³¹ = 18070087877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20217571529) 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 23 ways as a sum of consecutive naturals, for example, 2062135 + ... + 2071915.

It is an arithmetic number, because the mean of its divisors is an integer number (1057556475).

Almost surely, 2^20217571525 is an apocalyptic number.

20217571525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20217571525 is a deficient number, since it is larger than the sum of its proper divisors (5163783875).

20217571525 is an equidigital number, since it uses as much as digits as its factorization.

20217571525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10809 (or 10804 counting only the distinct ones).

The product of its (nonzero) digits is 49000, while the sum is 37.

The spelling of 20217571525 in words is "twenty billion, two hundred seventeen million, five hundred seventy-one thousand, five hundred twenty-five".