66215447 has 2 divisors, whose sum is σ = 66215448. Its totient is φ = 66215446.

The previous prime is 66215441. The next prime is 66215467. The reversal of 66215447 is 74451266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66215447 - 2⁴ = 66215431 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66215441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33107723 + 33107724.

It is an arithmetic number, because the mean of its divisors is an integer number (33107724).

Almost surely, 2^66215447 is an apocalyptic number.

66215447 is a deficient number, since it is larger than the sum of its proper divisors (1).

66215447 is an equidigital number, since it uses as much as digits as its factorization.

66215447 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 35.

The square root of 66215447 is about 8137.2874473009. The cubic root of 66215447 is about 404.5632583045.

The spelling of 66215447 in words is "sixty-six million, two hundred fifteen thousand, four hundred forty-seven".