66550551 has 8 divisors (see below), whose sum is σ = 89731440. Its totient is φ = 43868352.

The previous prime is 66550537. The next prime is 66550553. The reversal of 66550551 is 15505566.

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

It is not a de Polignac number, because 66550551 - 2⁶ = 66550487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66550553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124360 + ... + 124893.

It is an arithmetic number, because the mean of its divisors is an integer number (11216430).

Almost surely, 2^66550551 is an apocalyptic number.

66550551 is a deficient number, since it is larger than the sum of its proper divisors (23180889).

66550551 is a wasteful number, since it uses less digits than its factorization.

66550551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249345.

The product of its (nonzero) digits is 22500, while the sum is 33.

The square root of 66550551 is about 8157.8521070193. The cubic root of 66550551 is about 405.2445832503.

The spelling of 66550551 in words is "sixty-six million, five hundred fifty thousand, five hundred fifty-one".