66791047 has 2 divisors, whose sum is σ = 66791048. Its totient is φ = 66791046.

The previous prime is 66791033. The next prime is 66791059. The reversal of 66791047 is 74019766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66791047 - 2¹¹ = 66788999 is a prime.

It is a super-2 number, since 2×66791047² = 8922087918712418, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66791017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33395523 + 33395524.

It is an arithmetic number, because the mean of its divisors is an integer number (33395524).

Almost surely, 2^66791047 is an apocalyptic number.

66791047 is a deficient number, since it is larger than the sum of its proper divisors (1).

66791047 is an equidigital number, since it uses as much as digits as its factorization.

66791047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 66791047 is about 8172.5789687222. The cubic root of 66791047 is about 405.7321451469.

The spelling of 66791047 in words is "sixty-six million, seven hundred ninety-one thousand, forty-seven".