665720047 has 2 divisors, whose sum is σ = 665720048. Its totient is φ = 665720046.

The previous prime is 665719979. The next prime is 665720057. The reversal of 665720047 is 740027566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665720047 - 2⁷ = 665719919 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 665719988 and 665720015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665720057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332860023 + 332860024.

It is an arithmetic number, because the mean of its divisors is an integer number (332860024).

Almost surely, 2^665720047 is an apocalyptic number.

665720047 is a deficient number, since it is larger than the sum of its proper divisors (1).

665720047 is an equidigital number, since it uses as much as digits as its factorization.

665720047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 70560, while the sum is 37.

The square root of 665720047 is about 25801.5512518143. The cubic root of 665720047 is about 873.1667946562.

The spelling of 665720047 in words is "six hundred sixty-five million, seven hundred twenty thousand, forty-seven".