641388613 has 4 divisors (see below), whose sum is σ = 642141388. Its totient is φ = 640635840.

The previous prime is 641388607. The next prime is 641388617. The reversal of 641388613 is 316883146.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 316883146 = 2 ⋅158441573.

It can be written as a sum of positive squares in 2 ways, for example, as 316199524 + 325189089 = 17782^2 + 18033^2 .

It is a cyclic number.

It is not a de Polignac number, because 641388613 - 2⁵ = 641388581 is a prime.

It is a super-2 number, since 2×641388613² = 822758705772127538, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641388617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 375108 + ... + 376813.

It is an arithmetic number, because the mean of its divisors is an integer number (160535347).

Almost surely, 2^641388613 is an apocalyptic number.

It is an amenable number.

641388613 is a deficient number, since it is larger than the sum of its proper divisors (752775).

641388613 is an equidigital number, since it uses as much as digits as its factorization.

641388613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 752774.

The product of its digits is 82944, while the sum is 40.

The square root of 641388613 is about 25325.6512848140. The cubic root of 641388613 is about 862.3966916242.

The spelling of 641388613 in words is "six hundred forty-one million, three hundred eighty-eight thousand, six hundred thirteen".