3987217565 has 4 divisors (see below), whose sum is σ = 4784661084. Its totient is φ = 3189774048.

The previous prime is 3987217561. The next prime is 3987217571. The reversal of 3987217565 is 5657127893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1505284804 + 2481932761 = 38798^2 + 49819^2 .

It is a cyclic number.

It is not a de Polignac number, because 3987217565 - 2² = 3987217561 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3987217561) 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 3 ways as a sum of consecutive naturals, for example, 398721752 + ... + 398721761.

It is an arithmetic number, because the mean of its divisors is an integer number (1196165271).

Almost surely, 2^3987217565 is an apocalyptic number.

It is an amenable number.

3987217565 is a deficient number, since it is larger than the sum of its proper divisors (797443519).

3987217565 is an equidigital number, since it uses as much as digits as its factorization.

3987217565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 797443518.

The product of its digits is 3175200, while the sum is 53.

The square root of 3987217565 is about 63144.4183202284. The cubic root of 3987217565 is about 1585.7083433771.

The spelling of 3987217565 in words is "three billion, nine hundred eighty-seven million, two hundred seventeen thousand, five hundred sixty-five".