66155671 has 2 divisors, whose sum is σ = 66155672. Its totient is φ = 66155670.

The previous prime is 66155657. The next prime is 66155693. The reversal of 66155671 is 17655166.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66155671 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66155671.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66155611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33077835 + 33077836.

It is an arithmetic number, because the mean of its divisors is an integer number (33077836).

Almost surely, 2^66155671 is an apocalyptic number.

66155671 is a deficient number, since it is larger than the sum of its proper divisors (1).

66155671 is an equidigital number, since it uses as much as digits as its factorization.

66155671 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37800, while the sum is 37.

The square root of 66155671 is about 8133.6136495410. The cubic root of 66155671 is about 404.4414818148.

The spelling of 66155671 in words is "sixty-six million, one hundred fifty-five thousand, six hundred seventy-one".