66549863 has 2 divisors, whose sum is σ = 66549864. Its totient is φ = 66549862.

The previous prime is 66549851. The next prime is 66549869. The reversal of 66549863 is 36894566.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66549863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66549869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33274931 + 33274932.

It is an arithmetic number, because the mean of its divisors is an integer number (33274932).

Almost surely, 2^66549863 is an apocalyptic number.

66549863 is a deficient number, since it is larger than the sum of its proper divisors (1).

66549863 is an equidigital number, since it uses as much as digits as its factorization.

66549863 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 47.

The square root of 66549863 is about 8157.8099389481. The cubic root of 66549863 is about 405.2431867718.

The spelling of 66549863 in words is "sixty-six million, five hundred forty-nine thousand, eight hundred sixty-three".