66356401 has 2 divisors, whose sum is σ = 66356402. Its totient is φ = 66356400.

The previous prime is 66356393. The next prime is 66356419. The reversal of 66356401 is 10465366.

66356401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66341025 + 15376 = 8145^2 + 124^2 .

It is a cyclic number.

It is not a de Polignac number, because 66356401 - 2³ = 66356393 is a prime.

It is not a weakly prime, because it can be changed into another prime (66356201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33178200 + 33178201.

It is an arithmetic number, because the mean of its divisors is an integer number (33178201).

Almost surely, 2^66356401 is an apocalyptic number.

It is an amenable number.

66356401 is a deficient number, since it is larger than the sum of its proper divisors (1).

66356401 is an equidigital number, since it uses as much as digits as its factorization.

66356401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 66356401 is about 8145.9438372726. The cubic root of 66356401 is about 404.8501218519.

The spelling of 66356401 in words is "sixty-six million, three hundred fifty-six thousand, four hundred one".