646575575641 has 2 divisors, whose sum is σ = 646575575642. Its totient is φ = 646575575640.

The previous prime is 646575575621. The next prime is 646575575651. The reversal of 646575575641 is 146575575646.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 645739209241 + 836366400 = 803579^2 + 28920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646575575641 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646575575641.

It is not a weakly prime, because it can be changed into another prime (646575575621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323287787820 + 323287787821.

It is an arithmetic number, because the mean of its divisors is an integer number (323287787821).

Almost surely, 2^646575575641 is an apocalyptic number.

It is an amenable number.

646575575641 is a deficient number, since it is larger than the sum of its proper divisors (1).

646575575641 is an equidigital number, since it uses as much as digits as its factorization.

646575575641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 105840000, while the sum is 61.

The spelling of 646575575641 in words is "six hundred forty-six billion, five hundred seventy-five million, five hundred seventy-five thousand, six hundred forty-one".