641637 has 6 divisors (see below), whose sum is σ = 926822. Its totient is φ = 427752.

The previous prime is 641633. The next prime is 641639. The reversal of 641637 is 736146.

641637 is nontrivially palindromic in base 15.

641637 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 641601 + 36 = 801^2 + 6^2 .

It is not a de Polignac number, because 641637 - 2² = 641633 is a prime.

It is a Duffinian number.

641637 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 641637.

It is a congruent 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 5 ways as a sum of consecutive naturals, for example, 35638 + ... + 35655.

2⁶⁴¹⁶³⁷ is an apocalyptic number.

It is an amenable number.

641637 is a deficient number, since it is larger than the sum of its proper divisors (285185).

641637 is a wasteful number, since it uses less digits than its factorization.

641637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71299 (or 71296 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 641637 is about 801.0224715949. The cubic root of 641637 is about 86.2508002446.

The spelling of 641637 in words is "six hundred forty-one thousand, six hundred thirty-seven".