66400601 has 2 divisors, whose sum is σ = 66400602. Its totient is φ = 66400600.

The previous prime is 66400597. The next prime is 66400627. The reversal of 66400601 is 10600466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65626201 + 774400 = 8101^2 + 880^2 .

It is a cyclic number.

It is not a de Polignac number, because 66400601 - 2² = 66400597 is a prime.

It is a super-2 number, since 2×66400601² = 8818079626322402, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66400661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33200300 + 33200301.

It is an arithmetic number, because the mean of its divisors is an integer number (33200301).

Almost surely, 2^66400601 is an apocalyptic number.

It is an amenable number.

66400601 is a deficient number, since it is larger than the sum of its proper divisors (1).

66400601 is an equidigital number, since it uses as much as digits as its factorization.

66400601 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 23.

The square root of 66400601 is about 8148.6563923140. The cubic root of 66400601 is about 404.9399921253.

The spelling of 66400601 in words is "sixty-six million, four hundred thousand, six hundred one".