66783553 has 8 divisors (see below), whose sum is σ = 67767840. Its totient is φ = 65804640.

The previous prime is 66783533. The next prime is 66783571. The reversal of 66783553 is 35538766.

66783553 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66783553 - 2²⁵ = 33229121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66783503) 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 7 ways as a sum of consecutive naturals, for example, 28326 + ... + 30592.

It is an arithmetic number, because the mean of its divisors is an integer number (8470980).

Almost surely, 2^66783553 is an apocalyptic number.

It is an amenable number.

66783553 is a deficient number, since it is larger than the sum of its proper divisors (984287).

66783553 is a wasteful number, since it uses less digits than its factorization.

66783553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2687.

The product of its digits is 453600, while the sum is 43.

The square root of 66783553 is about 8172.1204714566. The cubic root of 66783553 is about 405.7169701070.

The spelling of 66783553 in words is "sixty-six million, seven hundred eighty-three thousand, five hundred fifty-three".