66749653 has 4 divisors (see below), whose sum is σ = 66769920. Its totient is φ = 66729388.

The previous prime is 66749647. The next prime is 66749659. The reversal of 66749653 is 35694766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (66749647) and next prime (66749659).

It is a cyclic number.

It is not a de Polignac number, because 66749653 - 2¹⁷ = 66618581 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 (66749659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3925 + ... + 12202.

It is an arithmetic number, because the mean of its divisors is an integer number (16692480).

Almost surely, 2^66749653 is an apocalyptic number.

It is an amenable number.

66749653 is a deficient number, since it is larger than the sum of its proper divisors (20267).

66749653 is a wasteful number, since it uses less digits than its factorization.

66749653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20266.

The product of its digits is 816480, while the sum is 46.

The square root of 66749653 is about 8170.0460831014. The cubic root of 66749653 is about 405.6483098230.

The spelling of 66749653 in words is "sixty-six million, seven hundred forty-nine thousand, six hundred fifty-three".