66623777 has 4 divisors (see below), whose sum is σ = 72680496. Its totient is φ = 60567060.

The previous prime is 66623761. The next prime is 66623779. The reversal of 66623777 is 77732666.

66623777 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 66623777 - 2⁴ = 66623761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66623779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3028343 + ... + 3028364.

It is an arithmetic number, because the mean of its divisors is an integer number (18170124).

Almost surely, 2^66623777 is an apocalyptic number.

It is an amenable number.

66623777 is a deficient number, since it is larger than the sum of its proper divisors (6056719).

66623777 is a wasteful number, since it uses less digits than its factorization.

66623777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6056718.

The product of its digits is 444528, while the sum is 44.

The square root of 66623777 is about 8162.3389417495. The cubic root of 66623777 is about 405.3931598456.

Subtracting 66623777 from its reverse (77732666), we obtain a square (11108889 = 3333²).

The spelling of 66623777 in words is "sixty-six million, six hundred twenty-three thousand, seven hundred seventy-seven".