66440447 has 2 divisors, whose sum is σ = 66440448. Its totient is φ = 66440446.

The previous prime is 66440401. The next prime is 66440467. The reversal of 66440447 is 74404466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66440447 - 2⁶ = 66440383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66440467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33220223 + 33220224.

It is an arithmetic number, because the mean of its divisors is an integer number (33220224).

Almost surely, 2^66440447 is an apocalyptic number.

66440447 is a deficient number, since it is larger than the sum of its proper divisors (1).

66440447 is an equidigital number, since it uses as much as digits as its factorization.

66440447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64512, while the sum is 35.

The square root of 66440447 is about 8151.1009685809. The cubic root of 66440447 is about 405.0209753908.

The spelling of 66440447 in words is "sixty-six million, four hundred forty thousand, four hundred forty-seven".