20685630625 has 45 divisors (see below), whose sum is σ = 28466707269. Its totient is φ = 15015330000.

The previous prime is 20685630599. The next prime is 20685630629. The reversal of 20685630625 is 52603658602.

It is a happy number.

The square root of 20685630625 is 143825.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1621753441 + 19063877184 = 40271^2 + 138072^2 .

It is not a de Polignac number, because 20685630625 - 2²¹ = 20683533473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20685630629) 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 44 ways as a sum of consecutive naturals, for example, 39551614 + ... + 39552136.

Almost surely, 2^20685630625 is an apocalyptic number.

20685630625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20685630625 is the 143825-th square number.

20685630625 is the 71913-rd centered octagonal number.

It is an amenable number.

20685630625 is a deficient number, since it is larger than the sum of its proper divisors (7781076644).

20685630625 is an frugal number, since it uses more digits than its factorization.

20685630625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088 (or 539 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 43.

The spelling of 20685630625 in words is "twenty billion, six hundred eighty-five million, six hundred thirty thousand, six hundred twenty-five".