1688117693261 has 2 divisors, whose sum is σ = 1688117693262. Its totient is φ = 1688117693260.

The previous prime is 1688117693183. The next prime is 1688117693279. The reversal of 1688117693261 is 1623967118861.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1128681011236 + 559436682025 = 1062394^2 + 747955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1688117693261 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1688117693261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1688117693461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844058846630 + 844058846631.

It is an arithmetic number, because the mean of its divisors is an integer number (844058846631).

Almost surely, 2^{1688117693261} is an apocalyptic number.

It is an amenable number.

1688117693261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688117693261 is an equidigital number, since it uses as much as digits as its factorization.

1688117693261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5225472, while the sum is 59.

The spelling of 1688117693261 in words is "one trillion, six hundred eighty-eight billion, one hundred seventeen million, six hundred ninety-three thousand, two hundred sixty-one".