685577775587 has 2 divisors, whose sum is σ = 685577775588. Its totient is φ = 685577775586.

The previous prime is 685577775551. The next prime is 685577775611. The reversal of 685577775587 is 785577775586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685577775587 - 2¹² = 685577771491 is a prime.

It is not a weakly prime, because it can be changed into another prime (685577775887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342788887793 + 342788887794.

It is an arithmetic number, because the mean of its divisors is an integer number (342788887794).

Almost surely, 2^685577775587 is an apocalyptic number.

685577775587 is a deficient number, since it is larger than the sum of its proper divisors (1).

685577775587 is an equidigital number, since it uses as much as digits as its factorization.

685577775587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4033680000, while the sum is 77.

Subtracting 685577775587 from its reverse (785577775586), we obtain a palindrome (99999999999).

The spelling of 685577775587 in words is "six hundred eighty-five billion, five hundred seventy-seven million, seven hundred seventy-five thousand, five hundred eighty-seven".