66490537 has 2 divisors, whose sum is σ = 66490538. Its totient is φ = 66490536.

The previous prime is 66490507. The next prime is 66490573. The reversal of 66490537 is 73509466.

Together with next prime (66490573) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37589161 + 28901376 = 6131^2 + 5376^2 .

It is a cyclic number.

It is not a de Polignac number, because 66490537 - 2⁷ = 66490409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66490537.

It is not a weakly prime, because it can be changed into another prime (66490507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33245268 + 33245269.

It is an arithmetic number, because the mean of its divisors is an integer number (33245269).

Almost surely, 2^66490537 is an apocalyptic number.

It is an amenable number.

66490537 is a deficient number, since it is larger than the sum of its proper divisors (1).

66490537 is an equidigital number, since it uses as much as digits as its factorization.

66490537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 136080, while the sum is 40.

The square root of 66490537 is about 8154.1729807504. The cubic root of 66490537 is about 405.1227327058.

The spelling of 66490537 in words is "sixty-six million, four hundred ninety thousand, five hundred thirty-seven".