641635587 has 20 divisors (see below), whose sum is σ = 978891936. Its totient is φ = 418653360.

The previous prime is 641635549. The next prime is 641635619. The reversal of 641635587 is 785536146.

641635587 is a `hidden beast` number, since 6 + 4 + 1 + 63 + 5 + 587 = 666.

It is not a de Polignac number, because 641635587 - 2⁷ = 641635459 is a prime.

It is not an unprimeable number, because it can be changed into a prime (641635507) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 80464 + ... + 88077.

Almost surely, 2^641635587 is an apocalyptic number.

641635587 is a deficient number, since it is larger than the sum of its proper divisors (337256349).

641635587 is a wasteful number, since it uses less digits than its factorization.

641635587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168600 (or 168591 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 641635587 is about 25330.5267809416. The cubic root of 641635587 is about 862.5073693132.

The spelling of 641635587 in words is "six hundred forty-one million, six hundred thirty-five thousand, five hundred eighty-seven".