689785064081 has 2 divisors, whose sum is σ = 689785064082. Its totient is φ = 689785064080.

The previous prime is 689785064071. The next prime is 689785064123. The reversal of 689785064081 is 180460587986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 554963911681 + 134821152400 = 744959^2 + 367180^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689785064081 is a prime.

It is a super-2 number, since 2×689785064081² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (689785064071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344892532040 + 344892532041.

It is an arithmetic number, because the mean of its divisors is an integer number (344892532041).

Almost surely, 2^689785064081 is an apocalyptic number.

It is an amenable number.

689785064081 is a deficient number, since it is larger than the sum of its proper divisors (1).

689785064081 is an equidigital number, since it uses as much as digits as its factorization.

689785064081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23224320, while the sum is 62.

The spelling of 689785064081 in words is "six hundred eighty-nine billion, seven hundred eighty-five million, sixty-four thousand, eighty-one".