641971536 has 20 divisors (see below), whose sum is σ = 1658426592. Its totient is φ = 213990496.

The previous prime is 641971531. The next prime is 641971537. The reversal of 641971536 is 635179146.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641971531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6687156 + ... + 6687251.

Almost surely, 2^641971536 is an apocalyptic number.

It is an amenable number.

641971536 is an abundant number, since it is smaller than the sum of its proper divisors (1016455056).

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

641971536 is a wasteful number, since it uses less digits than its factorization.

641971536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13374418 (or 13374412 counting only the distinct ones).

The product of its digits is 136080, while the sum is 42.

The square root of 641971536 is about 25337.1572201776. The cubic root of 641971536 is about 862.6578742301.

The spelling of 641971536 in words is "six hundred forty-one million, nine hundred seventy-one thousand, five hundred thirty-six".