617698681 has 2 divisors, whose sum is σ = 617698682. Its totient is φ = 617698680.

The previous prime is 617698673. The next prime is 617698687. The reversal of 617698681 is 186896716.

It is a happy number.

617698681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 605160000 + 12538681 = 24600^2 + 3541^2 .

It is a cyclic number.

It is not a de Polignac number, because 617698681 - 2³ = 617698673 is a prime.

It is a super-2 number, since 2×617698681² = 763103321018279522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (617698687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 308849340 + 308849341.

It is an arithmetic number, because the mean of its divisors is an integer number (308849341).

Almost surely, 2^617698681 is an apocalyptic number.

It is an amenable number.

617698681 is a deficient number, since it is larger than the sum of its proper divisors (1).

617698681 is an equidigital number, since it uses as much as digits as its factorization.

617698681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 52.

The square root of 617698681 is about 24853.5446365302. The cubic root of 617698681 is about 851.6455692750.

The spelling of 617698681 in words is "six hundred seventeen million, six hundred ninety-eight thousand, six hundred eighty-one".