641265536 has 64 divisors (see below), whose sum is σ = 1315163520. Its totient is φ = 311281152.

The previous prime is 641265511. The next prime is 641265557. The reversal of 641265536 is 635562146.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×641265536² = 822442975322734592, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 641265536.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1447331 + ... + 1447773.

It is an arithmetic number, because the mean of its divisors is an integer number (20549430).

Almost surely, 2^641265536 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641265536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (657581760).

641265536 is an abundant number, since it is smaller than the sum of its proper divisors (673897984).

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

641265536 is a wasteful number, since it uses less digits than its factorization.

641265536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 763 (or 751 counting only the distinct ones).

The product of its digits is 129600, while the sum is 38.

The square root of 641265536 is about 25323.2212800820. The cubic root of 641265536 is about 862.3415259075.

The spelling of 641265536 in words is "six hundred forty-one million, two hundred sixty-five thousand, five hundred thirty-six".