1678742693 has 2 divisors, whose sum is σ = 1678742694. Its totient is φ = 1678742692.

The previous prime is 1678742677. The next prime is 1678742743. The reversal of 1678742693 is 3962478761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1165403044 + 513339649 = 34138^2 + 22657^2 .

It is a cyclic number.

It is not a de Polignac number, because 1678742693 - 2⁴ = 1678742677 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1678742603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839371346 + 839371347.

It is an arithmetic number, because the mean of its divisors is an integer number (839371347).

Almost surely, 2^1678742693 is an apocalyptic number.

It is an amenable number.

1678742693 is a deficient number, since it is larger than the sum of its proper divisors (1).

1678742693 is an equidigital number, since it uses as much as digits as its factorization.

1678742693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 53.

The square root of 1678742693 is about 40972.4626182025. The cubic root of 1678742693 is about 1188.4877556401.

The spelling of 1678742693 in words is "one billion, six hundred seventy-eight million, seven hundred forty-two thousand, six hundred ninety-three".