641684623 has 2 divisors, whose sum is σ = 641684624. Its totient is φ = 641684622.

The previous prime is 641684597. The next prime is 641684633. The reversal of 641684623 is 326486146.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 641684623 - 2⁹ = 641684111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641684633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320842311 + 320842312.

It is an arithmetic number, because the mean of its divisors is an integer number (320842312).

Almost surely, 2^641684623 is an apocalyptic number.

641684623 is a deficient number, since it is larger than the sum of its proper divisors (1).

641684623 is an equidigital number, since it uses as much as digits as its factorization.

641684623 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 165888, while the sum is 40.

The square root of 641684623 is about 25331.4946854701. The cubic root of 641684623 is about 862.5293406808.

The spelling of 641684623 in words is "six hundred forty-one million, six hundred eighty-four thousand, six hundred twenty-three".