66947455 has 4 divisors (see below), whose sum is σ = 80336952. Its totient is φ = 53557960.

The previous prime is 66947449. The next prime is 66947459. The reversal of 66947455 is 55474966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55474966 = 2 ⋅27737483.

It is not a de Polignac number, because 66947455 - 2⁷ = 66947327 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66947459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6694741 + ... + 6694750.

It is an arithmetic number, because the mean of its divisors is an integer number (20084238).

Almost surely, 2^66947455 is an apocalyptic number.

66947455 is a deficient number, since it is larger than the sum of its proper divisors (13389497).

66947455 is a wasteful number, since it uses less digits than its factorization.

66947455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13389496.

The product of its digits is 907200, while the sum is 46.

The square root of 66947455 is about 8182.1424455946. The cubic root of 66947455 is about 406.0486061344.

The spelling of 66947455 in words is "sixty-six million, nine hundred forty-seven thousand, four hundred fifty-five".