685554140377 has 2 divisors, whose sum is σ = 685554140378. Its totient is φ = 685554140376.

The previous prime is 685554140303. The next prime is 685554140441. The reversal of 685554140377 is 773041455586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 483176521881 + 202377618496 = 695109^2 + 449864^2 .

It is a cyclic number.

It is not a de Polignac number, because 685554140377 - 2¹¹ = 685554138329 is a prime.

It is not a weakly prime, because it can be changed into another prime (685554140077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342777070188 + 342777070189.

It is an arithmetic number, because the mean of its divisors is an integer number (342777070189).

Almost surely, 2^685554140377 is an apocalyptic number.

It is an amenable number.

685554140377 is a deficient number, since it is larger than the sum of its proper divisors (1).

685554140377 is an equidigital number, since it uses as much as digits as its factorization.

685554140377 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112000, while the sum is 55.

The spelling of 685554140377 in words is "six hundred eighty-five billion, five hundred fifty-four million, one hundred forty thousand, three hundred seventy-seven".