1691798393 has 2 divisors, whose sum is σ = 1691798394. Its totient is φ = 1691798392.

The previous prime is 1691798387. The next prime is 1691798443. The reversal of 1691798393 is 3938971961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1395545449 + 296252944 = 37357^2 + 17212^2 .

It is a cyclic number.

It is not a de Polignac number, because 1691798393 - 2⁸ = 1691798137 is a prime.

It is not a weakly prime, because it can be changed into another prime (1691798363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845899196 + 845899197.

It is an arithmetic number, because the mean of its divisors is an integer number (845899197).

Almost surely, 2^1691798393 is an apocalyptic number.

It is an amenable number.

1691798393 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691798393 is an equidigital number, since it uses as much as digits as its factorization.

1691798393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 56.

The square root of 1691798393 is about 41131.4769124572. The cubic root of 1691798393 is about 1191.5607872502.

The spelling of 1691798393 in words is "one billion, six hundred ninety-one million, seven hundred ninety-eight thousand, three hundred ninety-three".