66198571 has 2 divisors, whose sum is σ = 66198572. Its totient is φ = 66198570.

The previous prime is 66198569. The next prime is 66198631. The reversal of 66198571 is 17589166.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66198571 - 2¹ = 66198569 is a prime.

Together with 66198569, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66198521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33099285 + 33099286.

It is an arithmetic number, because the mean of its divisors is an integer number (33099286).

Almost surely, 2^66198571 is an apocalyptic number.

66198571 is a deficient number, since it is larger than the sum of its proper divisors (1).

66198571 is an equidigital number, since it uses as much as digits as its factorization.

66198571 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 66198571 is about 8136.2504263328. The cubic root of 66198571 is about 404.5288857124.

The spelling of 66198571 in words is "sixty-six million, one hundred ninety-eight thousand, five hundred seventy-one".