641344536 has 72 divisors (see below), whose sum is σ = 2020573620. Its totient is φ = 183240288.

The previous prime is 641344531. The next prime is 641344537. The reversal of 641344536 is 635443146.

641344536 is a `hidden beast` number, since 641 + 3 + 4 + 4 + 5 + 3 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×641344536² = 822645627714110592, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 641344536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641344531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 87366 + ... + 94421.

Almost surely, 2^641344536 is an apocalyptic number.

It is an amenable number.

641344536 is an abundant number, since it is smaller than the sum of its proper divisors (1379229084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

641344536 is a wasteful number, since it uses less digits than its factorization.

641344536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181813 (or 181799 counting only the distinct ones).

The product of its digits is 103680, while the sum is 36.

The square root of 641344536 is about 25324.7810651938. The cubic root of 641344536 is about 862.3769361910.

The spelling of 641344536 in words is "six hundred forty-one million, three hundred forty-four thousand, five hundred thirty-six".