66642047 has 2 divisors, whose sum is σ = 66642048. Its totient is φ = 66642046.

The previous prime is 66642011. The next prime is 66642049. The reversal of 66642047 is 74024666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66642047 - 2⁶ = 66641983 is a prime.

Together with 66642049, it forms a pair of twin primes.

It is a Chen prime.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 66641998 and 66642016.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66642049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33321023 + 33321024.

It is an arithmetic number, because the mean of its divisors is an integer number (33321024).

Almost surely, 2^66642047 is an apocalyptic number.

66642047 is a deficient number, since it is larger than the sum of its proper divisors (1).

66642047 is an equidigital number, since it uses as much as digits as its factorization.

66642047 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 35.

The square root of 66642047 is about 8163.4580295363. The cubic root of 66642047 is about 405.4302129641.

The spelling of 66642047 in words is "sixty-six million, six hundred forty-two thousand, forty-seven".