665152251565 has 32 divisors (see below), whose sum is σ = 807673361760. Its totient is φ = 525837312000.

The previous prime is 665152251563. The next prime is 665152251593. The reversal of 665152251565 is 565152251566.

It can be written as a sum of positive squares in 16 ways, for example, as 1680098121 + 663472153444 = 40989^2 + 814538^2 .

It is not a de Polignac number, because 665152251565 - 2¹ = 665152251563 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665152251563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 237468165 + ... + 237470965.

It is an arithmetic number, because the mean of its divisors is an integer number (25239792555).

Almost surely, 2^665152251565 is an apocalyptic number.

It is an amenable number.

665152251565 is a deficient number, since it is larger than the sum of its proper divisors (142521110195).

665152251565 is a wasteful number, since it uses less digits than its factorization.

665152251565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4513.

The product of its digits is 2700000, while the sum is 49.

Subtracting from 665152251565 its reverse (565152251566), we obtain a palindrome (99999999999).

The spelling of 665152251565 in words is "six hundred sixty-five billion, one hundred fifty-two million, two hundred fifty-one thousand, five hundred sixty-five".