491316077657 has 2 divisors, whose sum is σ = 491316077658. Its totient is φ = 491316077656.

The previous prime is 491316077627. The next prime is 491316077719. The reversal of 491316077657 is 756770613194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 491115033616 + 201044041 = 700796^2 + 14179^2 .

It is a cyclic number.

It is not a de Polignac number, because 491316077657 - 2¹² = 491316073561 is a prime.

It is not a weakly prime, because it can be changed into another prime (491316077627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245658038828 + 245658038829.

It is an arithmetic number, because the mean of its divisors is an integer number (245658038829).

Almost surely, 2^491316077657 is an apocalyptic number.

It is an amenable number.

491316077657 is a deficient number, since it is larger than the sum of its proper divisors (1).

491316077657 is an equidigital number, since it uses as much as digits as its factorization.

491316077657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6667920, while the sum is 56.

The spelling of 491316077657 in words is "four hundred ninety-one billion, three hundred sixteen million, seventy-seven thousand, six hundred fifty-seven".