66231901 has 2 divisors, whose sum is σ = 66231902. Its totient is φ = 66231900.

The previous prime is 66231889. The next prime is 66231923. The reversal of 66231901 is 10913266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44235801 + 21996100 = 6651^2 + 4690^2 .

It is a cyclic number.

It is not a de Polignac number, because 66231901 - 2⁷ = 66231773 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66231901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66231101) 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 as a sum of consecutive naturals, namely, 33115950 + 33115951.

It is an arithmetic number, because the mean of its divisors is an integer number (33115951).

Almost surely, 2^66231901 is an apocalyptic number.

It is an amenable number.

66231901 is a deficient number, since it is larger than the sum of its proper divisors (1).

66231901 is an equidigital number, since it uses as much as digits as its factorization.

66231901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 66231901 is about 8138.2984093728. The cubic root of 66231901 is about 404.5967657556.

The spelling of 66231901 in words is "sixty-six million, two hundred thirty-one thousand, nine hundred one".