66748901 has 4 divisors (see below), whose sum is σ = 67437132. Its totient is φ = 66060672.

The previous prime is 66748897. The next prime is 66748909. The reversal of 66748901 is 10984766.

It is a Cunningham number, because it is equal to 8170²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29964676 + 36784225 = 5474^2 + 6065^2 .

It is a cyclic number.

It is not a de Polignac number, because 66748901 - 2² = 66748897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66748909) 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, 343970 + ... + 344163.

It is an arithmetic number, because the mean of its divisors is an integer number (16859283).

Almost surely, 2^66748901 is an apocalyptic number.

It is an amenable number.

66748901 is a deficient number, since it is larger than the sum of its proper divisors (688231).

66748901 is an equidigital number, since it uses as much as digits as its factorization.

66748901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688230.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 66748901 is about 8170.0000611995. Note that the first 4 decimals coincide. The cubic root of 66748901 is about 405.6467864759.

The spelling of 66748901 in words is "sixty-six million, seven hundred forty-eight thousand, nine hundred one".