66748551 has 4 divisors (see below), whose sum is σ = 88998072. Its totient is φ = 44499032.

The previous prime is 66748547. The next prime is 66748559. The reversal of 66748551 is 15584766.

66748551 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.

It is a cyclic number.

It is not a de Polignac number, because 66748551 - 2² = 66748547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66748559) 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, 11124756 + ... + 11124761.

It is an arithmetic number, because the mean of its divisors is an integer number (22249518).

Almost surely, 2^66748551 is an apocalyptic number.

66748551 is a deficient number, since it is larger than the sum of its proper divisors (22249521).

66748551 is a wasteful number, since it uses less digits than its factorization.

66748551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22249520.

The product of its digits is 201600, while the sum is 42.

The square root of 66748551 is about 8169.9786413430. The cubic root of 66748551 is about 405.6460774674.

It can be divided in two parts, 6674 and 8551, that added together give a triangular number (15225 = T₁₇₄).

The spelling of 66748551 in words is "sixty-six million, seven hundred forty-eight thousand, five hundred fifty-one".