641685493 has 4 divisors (see below), whose sum is σ = 641904448. Its totient is φ = 641466540.

The previous prime is 641685467. The next prime is 641685497. The reversal of 641685493 is 394586146.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 641685493 - 2¹³ = 641677301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641685497) 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, 105021 + ... + 110962.

It is an arithmetic number, because the mean of its divisors is an integer number (160476112).

Almost surely, 2^641685493 is an apocalyptic number.

It is an amenable number.

641685493 is a deficient number, since it is larger than the sum of its proper divisors (218955).

641685493 is a wasteful number, since it uses less digits than its factorization.

641685493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218954.

The product of its digits is 622080, while the sum is 46.

The square root of 641685493 is about 25331.5118577632. The cubic root of 641685493 is about 862.5297304882.

The spelling of 641685493 in words is "six hundred forty-one million, six hundred eighty-five thousand, four hundred ninety-three".