66672751 has 4 divisors (see below), whose sum is σ = 66690000. Its totient is φ = 66655504.

The previous prime is 66672737. The next prime is 66672787. The reversal of 66672751 is 15727666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15727666 = 2 ⋅7863833.

It is a cyclic number.

It is not a de Polignac number, because 66672751 - 2¹⁷ = 66541679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66672721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 150 + ... + 11548.

It is an arithmetic number, because the mean of its divisors is an integer number (16672500).

Almost surely, 2^66672751 is an apocalyptic number.

66672751 is a deficient number, since it is larger than the sum of its proper divisors (17249).

66672751 is a wasteful number, since it uses less digits than its factorization.

66672751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17248.

The product of its digits is 105840, while the sum is 40.

The square root of 66672751 is about 8165.3383885789. The cubic root of 66672751 is about 405.4924680444.

The spelling of 66672751 in words is "sixty-six million, six hundred seventy-two thousand, seven hundred fifty-one".