641744621 has 6 divisors (see below), whose sum is σ = 746519310. Its totient is φ = 550066776.

The previous prime is 641744603. The next prime is 641744657. The reversal of 641744621 is 126447146.

641744621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 405015625 + 236728996 = 20125^2 + 15386^2 .

It is a de Polignac number, because none of the positive numbers 2^k-641744621 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641744821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6548366 + ... + 6548463.

It is an arithmetic number, because the mean of its divisors is an integer number (124419885).

Almost surely, 2^641744621 is an apocalyptic number.

It is an amenable number.

641744621 is a deficient number, since it is larger than the sum of its proper divisors (104774689).

641744621 is a wasteful number, since it uses less digits than its factorization.

641744621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13096843 (or 13096836 counting only the distinct ones).

The product of its digits is 32256, while the sum is 35.

The square root of 641744621 is about 25332.6789147930. The cubic root of 641744621 is about 862.5562222260.

The spelling of 641744621 in words is "six hundred forty-one million, seven hundred forty-four thousand, six hundred twenty-one".