654561639673 has 2 divisors, whose sum is σ = 654561639674. Its totient is φ = 654561639672.

The previous prime is 654561639653. The next prime is 654561639731. The reversal of 654561639673 is 376936165456.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 615013555984 + 39548083689 = 784228^2 + 198867^2 .

It is a cyclic number.

It is not a de Polignac number, because 654561639673 - 2²¹ = 654559542521 is a prime.

It is not a weakly prime, because it can be changed into another prime (654561639643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327280819836 + 327280819837.

It is an arithmetic number, because the mean of its divisors is an integer number (327280819837).

Almost surely, 2^654561639673 is an apocalyptic number.

It is an amenable number.

654561639673 is a deficient number, since it is larger than the sum of its proper divisors (1).

654561639673 is an equidigital number, since it uses as much as digits as its factorization.

654561639673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 73483200, while the sum is 61.

The spelling of 654561639673 in words is "six hundred fifty-four billion, five hundred sixty-one million, six hundred thirty-nine thousand, six hundred seventy-three".