685577775551 has 2 divisors, whose sum is σ = 685577775552. Its totient is φ = 685577775550.

The previous prime is 685577775539. The next prime is 685577775587. The reversal of 685577775551 is 155577775586.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 685577775551 - 2¹⁰ = 685577774527 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685577775511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342788887775 + 342788887776.

It is an arithmetic number, because the mean of its divisors is an integer number (342788887776).

Almost surely, 2^685577775551 is an apocalyptic number.

685577775551 is a deficient number, since it is larger than the sum of its proper divisors (1).

685577775551 is an equidigital number, since it uses as much as digits as its factorization.

685577775551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360150000, while the sum is 68.

The spelling of 685577775551 in words is "six hundred eighty-five billion, five hundred seventy-seven million, seven hundred seventy-five thousand, five hundred fifty-one".