66854247 has 4 divisors (see below), whose sum is σ = 89139000. Its totient is φ = 44569496.

The previous prime is 66854237. The next prime is 66854273. The reversal of 66854247 is 74245866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66854247 - 2¹⁵ = 66821479 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66854199 and 66854208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66854237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11142372 + ... + 11142377.

It is an arithmetic number, because the mean of its divisors is an integer number (22284750).

Almost surely, 2^66854247 is an apocalyptic number.

66854247 is a deficient number, since it is larger than the sum of its proper divisors (22284753).

66854247 is a wasteful number, since it uses less digits than its factorization.

66854247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22284752.

The product of its digits is 322560, while the sum is 42.

The square root of 66854247 is about 8176.4446429973. Note that the first 3 decimals coincide. The cubic root of 66854247 is about 405.8600774029.

It can be divided in two parts, 6 and 6854247, that added together give a triangular number (6854253 = T₃₇₀₂).

The spelling of 66854247 in words is "sixty-six million, eight hundred fifty-four thousand, two hundred forty-seven".