7198785661 has 2 divisors, whose sum is σ = 7198785662. Its totient is φ = 7198785660.

The previous prime is 7198785653. The next prime is 7198785673. The reversal of 7198785661 is 1665878917.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6371072761 + 827712900 = 79819^2 + 28770^2 .

It is an emirp because it is prime and its reverse (1665878917) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7198785661 - 2³ = 7198785653 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 7198785596 and 7198785605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7198785611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3599392830 + 3599392831.

It is an arithmetic number, because the mean of its divisors is an integer number (3599392831).

Almost surely, 2^7198785661 is an apocalyptic number.

It is an amenable number.

7198785661 is a deficient number, since it is larger than the sum of its proper divisors (1).

7198785661 is an equidigital number, since it uses as much as digits as its factorization.

7198785661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5080320, while the sum is 58.

The square root of 7198785661 is about 84845.6578794696. The cubic root of 7198785661 is about 1930.8702046434.

The spelling of 7198785661 in words is "seven billion, one hundred ninety-eight million, seven hundred eighty-five thousand, six hundred sixty-one".