20556031225 has 12 divisors (see below), whose sum is σ = 25538232016. Its totient is φ = 16413371280.

The previous prime is 20556031217. The next prime is 20556031229. The reversal of 20556031225 is 52213065502.

It is a happy number.

It is not a de Polignac number, because 20556031225 - 2³ = 20556031217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20556031229) 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 11 ways as a sum of consecutive naturals, for example, 773007 + ... + 799156.

Almost surely, 2^20556031225 is an apocalyptic number.

20556031225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20556031225 is a deficient number, since it is larger than the sum of its proper divisors (4982200791).

20556031225 is a wasteful number, since it uses less digits than its factorization.

20556031225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1572696 (or 1572691 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 20556031225 its reverse (52213065502), we get a palindrome (72769096727).

The spelling of 20556031225 in words is "twenty billion, five hundred fifty-six million, thirty-one thousand, two hundred twenty-five".