66204491 has 2 divisors, whose sum is σ = 66204492. Its totient is φ = 66204490.

The previous prime is 66204461. The next prime is 66204497. The reversal of 66204491 is 19440266.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66204491 - 2⁶ = 66204427 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66204497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33102245 + 33102246.

It is an arithmetic number, because the mean of its divisors is an integer number (33102246).

Almost surely, 2^66204491 is an apocalyptic number.

66204491 is a deficient number, since it is larger than the sum of its proper divisors (1).

66204491 is an equidigital number, since it uses as much as digits as its factorization.

66204491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 66204491 is about 8136.6142221442. The cubic root of 66204491 is about 404.5409440775.

It can be divided in two parts, 6620 and 4491, that added together give a palindrome (11111).

The spelling of 66204491 in words is "sixty-six million, two hundred four thousand, four hundred ninety-one".