442661993 has 2 divisors, whose sum is σ = 442661994. Its totient is φ = 442661992.

The previous prime is 442661977. The next prime is 442662013. The reversal of 442661993 is 399166244.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 442345024 + 316969 = 21032^2 + 563^2 .

It is a cyclic number.

It is not a de Polignac number, because 442661993 - 2⁴ = 442661977 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (442661903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221330996 + 221330997.

It is an arithmetic number, because the mean of its divisors is an integer number (221330997).

Almost surely, 2^442661993 is an apocalyptic number.

It is an amenable number.

442661993 is a deficient number, since it is larger than the sum of its proper divisors (1).

442661993 is an equidigital number, since it uses as much as digits as its factorization.

442661993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 44.

The square root of 442661993 is about 21039.5340490230. The cubic root of 442661993 is about 762.1212627034.

The spelling of 442661993 in words is "four hundred forty-two million, six hundred sixty-one thousand, nine hundred ninety-three".