196662821 has 2 divisors, whose sum is σ = 196662822. Its totient is φ = 196662820.

The previous prime is 196662769. The next prime is 196662847. The reversal of 196662821 is 128266691.

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., 127938721 + 68724100 = 11311^2 + 8290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-196662821 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 (190662821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98331410 + 98331411.

It is an arithmetic number, because the mean of its divisors is an integer number (98331411).

Almost surely, 2^196662821 is an apocalyptic number.

It is an amenable number.

196662821 is a deficient number, since it is larger than the sum of its proper divisors (1).

196662821 is an equidigital number, since it uses as much as digits as its factorization.

196662821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 41.

The square root of 196662821 is about 14023.6521990529. The cubic root of 196662821 is about 581.5326300224.

The spelling of 196662821 in words is "one hundred ninety-six million, six hundred sixty-two thousand, eight hundred twenty-one".