20171100625 has 135 divisors (see below), whose sum is σ = 30112875639. Its totient is φ = 13498056000.

The previous prime is 20171100569. The next prime is 20171100629. The reversal of 20171100625 is 52600117102.

The square root of 20171100625 is 142025.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 7 ways, for example, as 19923604801 + 247495824 = 141151^2 + 15732^2 .

It is not a de Polignac number, because 20171100625 - 2¹⁹ = 20170576337 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20171100625.

It is not an unprimeable number, because it can be changed into a prime (20171100629) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 877004364 + ... + 877004386.

Almost surely, 2^20171100625 is an apocalyptic number.

20171100625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20171100625 is the 142025-th square number.

20171100625 is the 71013-rd centered octagonal number.

It is an amenable number.

20171100625 is a deficient number, since it is larger than the sum of its proper divisors (9941775014).

20171100625 is an equidigital number, since it uses as much as digits as its factorization.

20171100625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

Multiplying 20171100625 by its sum of digits (25), we get a square (504277515625 = 710125²).

20171100625 divided by its sum of digits (25) gives a square (806844025 = 28405²).

Adding to 20171100625 its reverse (52600117102), we get a palindrome (72771217727).

The spelling of 20171100625 in words is "twenty billion, one hundred seventy-one million, one hundred thousand, six hundred twenty-five".