16505825625 has 75 divisors (see below), whose sum is σ = 30865255113. Its totient is φ = 8787690000.

The previous prime is 16505825591. The next prime is 16505825641. The reversal of 16505825625 is 52652850561.

The square root of 16505825625 is 128475.

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

16505825625 is a `hidden beast` number, since 1 + 6 + 5 + 0 + 5 + 82 + 562 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1294056729 + 15211768896 = 35973^2 + 123336^2 .

It is a tau number, because it is divible by the number of its divisors (75).

It is a de Polignac number, because none of the positive numbers 2^k-16505825625 is a prime.

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

It is an unprimeable number.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 28906590 + ... + 28907160.

Almost surely, 2^16505825625 is an apocalyptic number.

16505825625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

16505825625 is the 128475-th square number.

16505825625 is the 64238-th centered octagonal number.

It is an amenable number.

16505825625 is a deficient number, since it is larger than the sum of its proper divisors (14359429488).

16505825625 is an frugal number, since it uses more digits than its factorization.

16505825625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1174 (or 579 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 45.

The spelling of 16505825625 in words is "sixteen billion, five hundred five million, eight hundred twenty-five thousand, six hundred twenty-five".