641635 has 4 divisors (see below), whose sum is σ = 769968. Its totient is φ = 513304.

The previous prime is 641633. The next prime is 641639. The reversal of 641635 is 536146.

641635 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 641635 - 2¹ = 641633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64159 + ... + 64168.

It is an arithmetic number, because the mean of its divisors is an integer number (192492).

2⁶⁴¹⁶³⁵ is an apocalyptic number.

641635 is a deficient number, since it is larger than the sum of its proper divisors (128333).

641635 is a wasteful number, since it uses less digits than its factorization.

641635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128332.

The product of its digits is 2160, while the sum is 25.

The square root of 641635 is about 801.0212231895. The cubic root of 641635 is about 86.2507106292.

The spelling of 641635 in words is "six hundred forty-one thousand, six hundred thirty-five".