181987065 has 48 divisors (see below), whose sum is σ = 342839952. Its totient is φ = 88768512.

The previous prime is 181987027. The next prime is 181987067. The reversal of 181987065 is 560789181.

It can be written as a sum of positive squares in 8 ways, for example, as 19501056 + 162486009 = 4416^2 + 12747^2 .

It is not a de Polignac number, because 181987065 - 2¹⁴ = 181970681 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 181987065.

It is not an unprimeable number, because it can be changed into a prime (181987067) 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 47 ways as a sum of consecutive naturals, for example, 64729 + ... + 67481.

It is an arithmetic number, because the mean of its divisors is an integer number (7142499).

Almost surely, 2^181987065 is an apocalyptic number.

181987065 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181987065 is a deficient number, since it is larger than the sum of its proper divisors (160852887).

181987065 is a wasteful number, since it uses less digits than its factorization.

181987065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2890 (or 2887 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

The square root of 181987065 is about 13490.2581517182. The cubic root of 181987065 is about 566.6916849777.

The spelling of 181987065 in words is "one hundred eighty-one million, nine hundred eighty-seven thousand, sixty-five".