66745451 has 4 divisors (see below), whose sum is σ = 70671672. Its totient is φ = 62819232.

The previous prime is 66745429. The next prime is 66745453. The reversal of 66745451 is 15454766.

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 66745451 - 2¹⁰ = 66744427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66745453) 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, 1963085 + ... + 1963118.

It is an arithmetic number, because the mean of its divisors is an integer number (17667918).

Almost surely, 2^66745451 is an apocalyptic number.

66745451 is a deficient number, since it is larger than the sum of its proper divisors (3926221).

66745451 is a wasteful number, since it uses less digits than its factorization.

66745451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3926220.

The product of its digits is 100800, while the sum is 38.

The square root of 66745451 is about 8169.7889201619. The cubic root of 66745451 is about 405.6397975692.

The spelling of 66745451 in words is "sixty-six million, seven hundred forty-five thousand, four hundred fifty-one".