66406537 has 2 divisors, whose sum is σ = 66406538. Its totient is φ = 66406536.

The previous prime is 66406519. The next prime is 66406541. The reversal of 66406537 is 73560466.

66406537 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66243321 + 163216 = 8139^2 + 404^2 .

It is a cyclic number.

It is not a de Polignac number, because 66406537 - 2⁷ = 66406409 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66406496 and 66406505.

It is not a weakly prime, because it can be changed into another prime (66406517) 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, 33203268 + 33203269.

It is an arithmetic number, because the mean of its divisors is an integer number (33203269).

Almost surely, 2^66406537 is an apocalyptic number.

It is an amenable number.

66406537 is a deficient number, since it is larger than the sum of its proper divisors (1).

66406537 is an equidigital number, since it uses as much as digits as its factorization.

66406537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 66406537 is about 8149.0206160004. The cubic root of 66406537 is about 404.9520585431.

The spelling of 66406537 in words is "sixty-six million, four hundred six thousand, five hundred thirty-seven".