66955771 has 2 divisors, whose sum is σ = 66955772. Its totient is φ = 66955770.

The previous prime is 66955729. The next prime is 66955799. The reversal of 66955771 is 17755966.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66955771 - 2⁷ = 66955643 is a prime.

It is not a weakly prime, because it can be changed into another prime (66955711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33477885 + 33477886.

It is an arithmetic number, because the mean of its divisors is an integer number (33477886).

Almost surely, 2^66955771 is an apocalyptic number.

66955771 is a deficient number, since it is larger than the sum of its proper divisors (1).

66955771 is an equidigital number, since it uses as much as digits as its factorization.

66955771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 396900, while the sum is 46.

The square root of 66955771 is about 8182.6506096741. The cubic root of 66955771 is about 406.0654181272.

The spelling of 66955771 in words is "sixty-six million, nine hundred fifty-five thousand, seven hundred seventy-one".