641656623 has 8 divisors (see below), whose sum is σ = 855875968. Its totient is φ = 427604184.

The previous prime is 641656597. The next prime is 641656633. The reversal of 641656623 is 326656146.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 641656623 - 2¹² = 641652527 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 (641656633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32461 + ... + 48342.

It is an arithmetic number, because the mean of its divisors is an integer number (106984496).

Almost surely, 2^641656623 is an apocalyptic number.

641656623 is a deficient number, since it is larger than the sum of its proper divisors (214219345).

641656623 is a wasteful number, since it uses less digits than its factorization.

641656623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83453.

The product of its digits is 155520, while the sum is 39.

The square root of 641656623 is about 25330.9420077501. The cubic root of 641656623 is about 862.5167949681.

The spelling of 641656623 in words is "six hundred forty-one million, six hundred fifty-six thousand, six hundred twenty-three".