6641531641 has 2 divisors, whose sum is σ = 6641531642. Its totient is φ = 6641531640.

The previous prime is 6641531597. The next prime is 6641531693. The reversal of 6641531641 is 1461351466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6479606016 + 161925625 = 80496^2 + 12725^2 .

It is a cyclic number.

It is not a de Polignac number, because 6641531641 - 2²¹ = 6639434489 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6641531641.

It is not a weakly prime, because it can be changed into another prime (6641531041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3320765820 + 3320765821.

It is an arithmetic number, because the mean of its divisors is an integer number (3320765821).

Almost surely, 2^6641531641 is an apocalyptic number.

It is an amenable number.

6641531641 is a deficient number, since it is larger than the sum of its proper divisors (1).

6641531641 is an equidigital number, since it uses as much as digits as its factorization.

6641531641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 37.

The square root of 6641531641 is about 81495.5927704069. The cubic root of 6641531641 is about 1879.7037824567.

The spelling of 6641531641 in words is "six billion, six hundred forty-one million, five hundred thirty-one thousand, six hundred forty-one".