66019651 has 2 divisors, whose sum is σ = 66019652. Its totient is φ = 66019650.

The previous prime is 66019649. The next prime is 66019669. The reversal of 66019651 is 15691066.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66019651 - 2¹ = 66019649 is a prime.

Together with 66019649, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66019621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33009825 + 33009826.

It is an arithmetic number, because the mean of its divisors is an integer number (33009826).

Almost surely, 2^66019651 is an apocalyptic number.

66019651 is a deficient number, since it is larger than the sum of its proper divisors (1).

66019651 is an equidigital number, since it uses as much as digits as its factorization.

66019651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 66019651 is about 8125.2477500689. The cubic root of 66019651 is about 404.1641063689.

The spelling of 66019651 in words is "sixty-six million, nineteen thousand, six hundred fifty-one".