66537109 has 2 divisors, whose sum is σ = 66537110. Its totient is φ = 66537108.

The previous prime is 66537103. The next prime is 66537131. The reversal of 66537109 is 90173566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49702500 + 16834609 = 7050^2 + 4103^2 .

It is a cyclic number.

It is not a de Polignac number, because 66537109 - 2⁹ = 66536597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66537103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33268554 + 33268555.

It is an arithmetic number, because the mean of its divisors is an integer number (33268555).

Almost surely, 2^66537109 is an apocalyptic number.

It is an amenable number.

66537109 is a deficient number, since it is larger than the sum of its proper divisors (1).

66537109 is an equidigital number, since it uses as much as digits as its factorization.

66537109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 37.

The square root of 66537109 is about 8157.0281965922. The cubic root of 66537109 is about 405.2172974032.

The spelling of 66537109 in words is "sixty-six million, five hundred thirty-seven thousand, one hundred nine".