641899 has 4 divisors (see below), whose sum is σ = 643536. Its totient is φ = 640264.

The previous prime is 641897. The next prime is 641909. The reversal of 641899 is 998146.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 641899 - 2¹ = 641897 is a prime.

It is a Duffinian number.

641899 is a lucky number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (641891) 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, 162 + ... + 1144.

It is an arithmetic number, because the mean of its divisors is an integer number (160884).

2⁶⁴¹⁸⁹⁹ is an apocalyptic number.

641899 is a deficient number, since it is larger than the sum of its proper divisors (1637).

641899 is an equidigital number, since it uses as much as digits as its factorization.

641899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1636.

The product of its digits is 15552, while the sum is 37.

The square root of 641899 is about 801.1859958836. The cubic root of 641899 is about 86.2625382598.

It can be divided in two parts, 641 and 899, that added together give a triangular number (1540 = T₅₅).

The spelling of 641899 in words is "six hundred forty-one thousand, eight hundred ninety-nine".