641198689 has 4 divisors (see below), whose sum is σ = 644521156. Its totient is φ = 637876224.

The previous prime is 641198659. The next prime is 641198759. The reversal of 641198689 is 986891146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 986891146 = 2 ⋅493445573.

It can be written as a sum of positive squares in 2 ways, for example, as 111830625 + 529368064 = 10575^2 + 23008^2 .

It is a cyclic number.

It is not a de Polignac number, because 641198689 - 2⁷ = 641198561 is a prime.

It is a super-2 number, since 2×641198689² = 822271517550637442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641198609) 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, 1660944 + ... + 1661329.

It is an arithmetic number, because the mean of its divisors is an integer number (161130289).

Almost surely, 2^641198689 is an apocalyptic number.

It is an amenable number.

641198689 is a deficient number, since it is larger than the sum of its proper divisors (3322467).

641198689 is a wasteful number, since it uses less digits than its factorization.

641198689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3322466.

The product of its digits is 746496, while the sum is 52.

The square root of 641198689 is about 25321.9013701578. The cubic root of 641198689 is about 862.3115607091.

The spelling of 641198689 in words is "six hundred forty-one million, one hundred ninety-eight thousand, six hundred eighty-nine".