66557143 has 2 divisors, whose sum is σ = 66557144. Its totient is φ = 66557142.

The previous prime is 66557131. The next prime is 66557173. The reversal of 66557143 is 34175566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66557143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66557173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33278571 + 33278572.

It is an arithmetic number, because the mean of its divisors is an integer number (33278572).

Almost surely, 2^66557143 is an apocalyptic number.

66557143 is a deficient number, since it is larger than the sum of its proper divisors (1).

66557143 is an equidigital number, since it uses as much as digits as its factorization.

66557143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75600, while the sum is 37.

The square root of 66557143 is about 8158.2561249326. The cubic root of 66557143 is about 405.2579629747.

The spelling of 66557143 in words is "sixty-six million, five hundred fifty-seven thousand, one hundred forty-three".