641307821 has 8 divisors (see below), whose sum is σ = 799552704. Its totient is φ = 499720320.

The previous prime is 641307803. The next prime is 641307829. The reversal of 641307821 is 128703146.

641307821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-641307821 is a prime.

It is a super-2 number, since 2×641307821² = 822551442551536082, 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 (641307829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4164260 + ... + 4164413.

It is an arithmetic number, because the mean of its divisors is an integer number (99944088).

Almost surely, 2^641307821 is an apocalyptic number.

It is an amenable number.

641307821 is a deficient number, since it is larger than the sum of its proper divisors (158244883).

641307821 is a wasteful number, since it uses less digits than its factorization.

641307821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8328691.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 641307821 is about 25324.0561719484. The cubic root of 641307821 is about 862.3604797355.

The spelling of 641307821 in words is "six hundred forty-one million, three hundred seven thousand, eight hundred twenty-one".