16508981745 has 72 divisors (see below), whose sum is σ = 30406881960. Its totient is φ = 8283179520.

The previous prime is 16508981737. The next prime is 16508981747. The reversal of 16508981745 is 54718980561.

It is a happy number.

16508981745 is a `hidden beast` number, since 1 + 6 + 508 + 98 + 1 + 7 + 45 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 55532304 + 16453449441 = 7452^2 + 128271^2 .

It is not a de Polignac number, because 16508981745 - 2³ = 16508981737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16508981691 and 16508981700.

It is not an unprimeable number, because it can be changed into a prime (16508981747) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1446421 + ... + 1457789.

It is an arithmetic number, because the mean of its divisors is an integer number (422317805).

Almost surely, 2^16508981745 is an apocalyptic number.

16508981745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

16508981745 is a deficient number, since it is larger than the sum of its proper divisors (13897900215).

16508981745 is a wasteful number, since it uses less digits than its factorization.

16508981745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11487 (or 11461 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 54.

The spelling of 16508981745 in words is "sixteen billion, five hundred eight million, nine hundred eighty-one thousand, seven hundred forty-five".