66445477 has 4 divisors (see below), whose sum is σ = 75937696. Its totient is φ = 56953260.

The previous prime is 66445447. The next prime is 66445487. The reversal of 66445477 is 77454466.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77454466 = 2 ⋅38727233.

It is a de Polignac number, because none of the positive numbers 2^k-66445477 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 (66445417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4746099 + ... + 4746112.

It is an arithmetic number, because the mean of its divisors is an integer number (18984424).

Almost surely, 2^66445477 is an apocalyptic number.

It is an amenable number.

66445477 is a deficient number, since it is larger than the sum of its proper divisors (9492219).

66445477 is an equidigital number, since it uses as much as digits as its factorization.

66445477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9492218.

The product of its digits is 564480, while the sum is 43.

The square root of 66445477 is about 8151.4095100173. The cubic root of 66445477 is about 405.0311960931.

It can be divided in two parts, 6644 and 5477, that added together give a palindrome (12121).

The spelling of 66445477 in words is "sixty-six million, four hundred forty-five thousand, four hundred seventy-seven".