66530491 has 2 divisors, whose sum is σ = 66530492. Its totient is φ = 66530490.

The previous prime is 66530473. The next prime is 66530501. The reversal of 66530491 is 19403566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66530491 - 2¹³ = 66522299 is a prime.

It is not a weakly prime, because it can be changed into another prime (66530411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33265245 + 33265246.

It is an arithmetic number, because the mean of its divisors is an integer number (33265246).

Almost surely, 2^66530491 is an apocalyptic number.

66530491 is a deficient number, since it is larger than the sum of its proper divisors (1).

66530491 is an equidigital number, since it uses as much as digits as its factorization.

66530491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 34.

The square root of 66530491 is about 8156.6225240598. The cubic root of 66530491 is about 405.2038622087.

The spelling of 66530491 in words is "sixty-six million, five hundred thirty thousand, four hundred ninety-one".