16556025402225 has 18 divisors (see below), whose sum is σ = 29653681054166. Its totient is φ = 8829880214400.

The previous prime is 16556025402221. The next prime is 16556025402289. The reversal of 16556025402225 is 52220452065561.

16556025402225 is a `hidden beast` number, since 1 + 6 + 5 + 5 + 60 + 2 + 540 + 22 + 25 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 116957844081 + 16439067558144 = 341991^2 + 4054512^2 .

It is not a de Polignac number, because 16556025402225 - 2² = 16556025402221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16556025402221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 36791167336 + ... + 36791167785.

Almost surely, 2^{16556025402225} is an apocalyptic number.

16556025402225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16556025402225 is a deficient number, since it is larger than the sum of its proper divisors (13097655651941).

16556025402225 is a wasteful number, since it uses less digits than its factorization.

16556025402225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73582335137 (or 73582335129 counting only the distinct ones).

The product of its (nonzero) digits is 1440000, while the sum is 45.

Adding to 16556025402225 its reverse (52220452065561), we get a palindrome (68776477467786).

The spelling of 16556025402225 in words is "sixteen trillion, five hundred fifty-six billion, twenty-five million, four hundred two thousand, two hundred twenty-five".