641687505 has 8 divisors (see below), whose sum is σ = 1026700032. Its totient is φ = 342233328.

The previous prime is 641687477. The next prime is 641687531. The reversal of 641687505 is 505786146.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 641687505 - 2⁹ = 641686993 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21389569 + ... + 21389598.

It is an arithmetic number, because the mean of its divisors is an integer number (128337504).

Almost surely, 2^641687505 is an apocalyptic number.

It is an amenable number.

641687505 is a deficient number, since it is larger than the sum of its proper divisors (385012527).

641687505 is a wasteful number, since it uses less digits than its factorization.

641687505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42779175.

The product of its (nonzero) digits is 201600, while the sum is 42.

The square root of 641687505 is about 25331.5515711138. The cubic root of 641687505 is about 862.5306319724.

The spelling of 641687505 in words is "six hundred forty-one million, six hundred eighty-seven thousand, five hundred five".