66499651 has 2 divisors, whose sum is σ = 66499652. Its totient is φ = 66499650.

The previous prime is 66499649. The next prime is 66499687. The reversal of 66499651 is 15699466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66499651 - 2¹ = 66499649 is a prime.

Together with 66499649, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66499621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33249825 + 33249826.

It is an arithmetic number, because the mean of its divisors is an integer number (33249826).

Almost surely, 2^66499651 is an apocalyptic number.

66499651 is a deficient number, since it is larger than the sum of its proper divisors (1).

66499651 is an equidigital number, since it uses as much as digits as its factorization.

66499651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 349920, while the sum is 46.

The square root of 66499651 is about 8154.7318165590. The cubic root of 66499651 is about 405.1412422064.

The spelling of 66499651 in words is "sixty-six million, four hundred ninety-nine thousand, six hundred fifty-one".