66444791 has 16 divisors (see below), whose sum is σ = 77220864. Its totient is φ = 55999104.

The previous prime is 66444787. The next prime is 66444803. The reversal of 66444791 is 19744466.

It is not a de Polignac number, because 66444791 - 2² = 66444787 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66444731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131846 + ... + 132348.

It is an arithmetic number, because the mean of its divisors is an integer number (4826304).

Almost surely, 2^66444791 is an apocalyptic number.

66444791 is a deficient number, since it is larger than the sum of its proper divisors (10776073).

66444791 is a wasteful number, since it uses less digits than its factorization.

66444791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790.

The product of its digits is 145152, while the sum is 41.

The square root of 66444791 is about 8151.3674312964. The cubic root of 66444791 is about 405.0298022067.

The spelling of 66444791 in words is "sixty-six million, four hundred forty-four thousand, seven hundred ninety-one".