641808 has 30 divisors (see below), whose sum is σ = 1796574. Its totient is φ = 213888.

The previous prime is 641803. The next prime is 641813. The reversal of 641808 is 808146.

It is an interprime number because it is at equal distance from previous prime (641803) and next prime (641813).

It can be written as a sum of positive squares in only one way, i.e., 589824 + 51984 = 768^2 + 228^2 .

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 641808.

It is not an unprimeable number, because it can be changed into a prime (641803) by changing a digit.

641808 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2085 + ... + 2372.

2⁶⁴¹⁸⁰⁸ is an apocalyptic number.

It is an amenable number.

641808 is an abundant number, since it is smaller than the sum of its proper divisors (1154766).

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

641808 is a wasteful number, since it uses less digits than its factorization.

641808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4471 (or 4462 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 641808 is about 801.1292030628. The cubic root of 641808 is about 86.2584616777.

It can be divided in two parts, 6 and 41808, that added together give a palindrome (41814).

The spelling of 641808 in words is "six hundred forty-one thousand, eight hundred eight".