641736913 has 4 divisors (see below), whose sum is σ = 675512560. Its totient is φ = 607961268.

The previous prime is 641736881. The next prime is 641736929. The reversal of 641736913 is 319637146.

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 641736913 - 2⁵ = 641736881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641736973) 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, 16887795 + ... + 16887832.

It is an arithmetic number, because the mean of its divisors is an integer number (168878140).

Almost surely, 2^641736913 is an apocalyptic number.

It is an amenable number.

641736913 is a deficient number, since it is larger than the sum of its proper divisors (33775647).

641736913 is a wasteful number, since it uses less digits than its factorization.

641736913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33775646.

The product of its digits is 81648, while the sum is 40.

The square root of 641736913 is about 25332.5267788273. The cubic root of 641736913 is about 862.5527688222.

The spelling of 641736913 in words is "six hundred forty-one million, seven hundred thirty-six thousand, nine hundred thirteen".