66138001 has 2 divisors, whose sum is σ = 66138002. Its totient is φ = 66138000.

The previous prime is 66137987. The next prime is 66138019. The reversal of 66138001 is 10083166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57017601 + 9120400 = 7551^2 + 3020^2 .

It is a cyclic number.

It is not a de Polignac number, because 66138001 - 2⁷ = 66137873 is a prime.

It is not a weakly prime, because it can be changed into another prime (66139001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33069000 + 33069001.

It is an arithmetic number, because the mean of its divisors is an integer number (33069001).

Almost surely, 2^66138001 is an apocalyptic number.

It is an amenable number.

66138001 is a deficient number, since it is larger than the sum of its proper divisors (1).

66138001 is an equidigital number, since it uses as much as digits as its factorization.

66138001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 66138001 is about 8132.5273439442. The cubic root of 66138001 is about 404.4054702014.

The spelling of 66138001 in words is "sixty-six million, one hundred thirty-eight thousand, one".