66659501 has 2 divisors, whose sum is σ = 66659502. Its totient is φ = 66659500.

The previous prime is 66659477. The next prime is 66659507. The reversal of 66659501 is 10595666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56987401 + 9672100 = 7549^2 + 3110^2 .

It is a cyclic number.

It is not a de Polignac number, because 66659501 - 2¹⁴ = 66643117 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66659507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33329750 + 33329751.

It is an arithmetic number, because the mean of its divisors is an integer number (33329751).

Almost surely, 2^66659501 is an apocalyptic number.

It is an amenable number.

66659501 is a deficient number, since it is larger than the sum of its proper divisors (1).

66659501 is an equidigital number, since it uses as much as digits as its factorization.

66659501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48600, while the sum is 38.

The square root of 66659501 is about 8164.5269918104. The cubic root of 66659501 is about 405.4656048403.

The spelling of 66659501 in words is "sixty-six million, six hundred fifty-nine thousand, five hundred one".