66954197 has 2 divisors, whose sum is σ = 66954198. Its totient is φ = 66954196.

The previous prime is 66954169. The next prime is 66954227. The reversal of 66954197 is 79145966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64625521 + 2328676 = 8039^2 + 1526^2 .

It is a cyclic number.

It is not a de Polignac number, because 66954197 - 2¹⁸ = 66692053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66951197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33477098 + 33477099.

It is an arithmetic number, because the mean of its divisors is an integer number (33477099).

Almost surely, 2^66954197 is an apocalyptic number.

It is an amenable number.

66954197 is a deficient number, since it is larger than the sum of its proper divisors (1).

66954197 is an equidigital number, since it uses as much as digits as its factorization.

66954197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 408240, while the sum is 47.

The square root of 66954197 is about 8182.5544300053. The cubic root of 66954197 is about 406.0622361661.

The spelling of 66954197 in words is "sixty-six million, nine hundred fifty-four thousand, one hundred ninety-seven".