641820531 has 8 divisors (see below), whose sum is σ = 933557184. Its totient is φ = 388982120.

The previous prime is 641820493. The next prime is 641820577. The reversal of 641820531 is 135028146.

641820531 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 cyclic number.

It is not a de Polignac number, because 641820531 - 2¹¹ = 641818483 is a prime.

It is a super-2 number, since 2×641820531² = 823867188026243922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (641820031) 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, 9724521 + ... + 9724586.

It is an arithmetic number, because the mean of its divisors is an integer number (116694648).

Almost surely, 2^641820531 is an apocalyptic number.

641820531 is a deficient number, since it is larger than the sum of its proper divisors (291736653).

641820531 is a wasteful number, since it uses less digits than its factorization.

641820531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19449121.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 641820531 is about 25334.1771328772. The cubic root of 641820531 is about 862.5902305938.

Adding to 641820531 its reverse (135028146), we get a palindrome (776848677).

The spelling of 641820531 in words is "six hundred forty-one million, eight hundred twenty thousand, five hundred thirty-one".