6545203661 has 2 divisors, whose sum is σ = 6545203662. Its totient is φ = 6545203660.

The previous prime is 6545203573. The next prime is 6545203751. The reversal of 6545203661 is 1663025456.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4745832100 + 1799371561 = 68890^2 + 42419^2 .

It is a cyclic number.

It is not a de Polignac number, because 6545203661 - 2¹⁸ = 6544941517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6545202661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3272601830 + 3272601831.

It is an arithmetic number, because the mean of its divisors is an integer number (3272601831).

Almost surely, 2^6545203661 is an apocalyptic number.

It is an amenable number.

6545203661 is a deficient number, since it is larger than the sum of its proper divisors (1).

6545203661 is an equidigital number, since it uses as much as digits as its factorization.

6545203661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 6545203661 is about 80902.4329733043. The cubic root of 6545203661 is about 1870.5718232763.

The spelling of 6545203661 in words is "six billion, five hundred forty-five million, two hundred three thousand, six hundred sixty-one".