645576216631201 has 2 divisors, whose sum is σ = 645576216631202. Its totient is φ = 645576216631200.

The previous prime is 645576216631193. The next prime is 645576216631267. The reversal of 645576216631201 is 102136612675546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 626090525283601 + 19485691347600 = 25021801^2 + 4414260^2 .

It is a cyclic number.

It is not a de Polignac number, because 645576216631201 - 2³ = 645576216631193 is a prime.

It is not a weakly prime, because it can be changed into another prime (645576216631001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322788108315600 + 322788108315601.

It is an arithmetic number, because the mean of its divisors is an integer number (322788108315601).

Almost surely, 2^{645576216631201} is an apocalyptic number.

It is an amenable number.

645576216631201 is a deficient number, since it is larger than the sum of its proper divisors (1).

645576216631201 is an equidigital number, since it uses as much as digits as its factorization.

645576216631201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10886400, while the sum is 55.

The spelling of 645576216631201 in words is "six hundred forty-five trillion, five hundred seventy-six billion, two hundred sixteen million, six hundred thirty-one thousand, two hundred one".