66447278 has 4 divisors (see below), whose sum is σ = 99670920. Its totient is φ = 33223638.

The previous prime is 66447259. The next prime is 66447281. The reversal of 66447278 is 87274466.

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

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 16611818 + ... + 16611821.

It is an arithmetic number, because the mean of its divisors is an integer number (24917730).

Almost surely, 2^66447278 is an apocalyptic number.

66447278 is a deficient number, since it is larger than the sum of its proper divisors (33223642).

66447278 is a wasteful number, since it uses less digits than its factorization.

66447278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33223641.

The product of its digits is 451584, while the sum is 44.

The square root of 66447278 is about 8151.5199809606. The cubic root of 66447278 is about 405.0348555075.

The spelling of 66447278 in words is "sixty-six million, four hundred forty-seven thousand, two hundred seventy-eight".