66542751 has 24 divisors (see below), whose sum is σ = 105328080. Its totient is φ = 40147200.

The previous prime is 66542717. The next prime is 66542753. The reversal of 66542751 is 15724566.

It is a happy number.

66542751 is a `hidden beast` number, since 66 + 542 + 7 + 51 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-66542751 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66542753) 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 23 ways as a sum of consecutive naturals, for example, 22465 + ... + 25253.

It is an arithmetic number, because the mean of its divisors is an integer number (4388670).

Almost surely, 2^66542751 is an apocalyptic number.

66542751 is a deficient number, since it is larger than the sum of its proper divisors (38785329).

66542751 is a wasteful number, since it uses less digits than its factorization.

66542751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3047 (or 3044 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The square root of 66542751 is about 8157.3740259964. The cubic root of 66542751 is about 405.2287505176.

The spelling of 66542751 in words is "sixty-six million, five hundred forty-two thousand, seven hundred fifty-one".