66693643 has 2 divisors, whose sum is σ = 66693644. Its totient is φ = 66693642.

The previous prime is 66693631. The next prime is 66693673. The reversal of 66693643 is 34639666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66693643 - 2²¹ = 64596491 is a prime.

It is a super-2 number, since 2×66693643² = 8896084033222898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66693643.

It is not a weakly prime, because it can be changed into another prime (66693623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33346821 + 33346822.

It is an arithmetic number, because the mean of its divisors is an integer number (33346822).

Almost surely, 2^66693643 is an apocalyptic number.

66693643 is a deficient number, since it is larger than the sum of its proper divisors (1).

66693643 is an equidigital number, since it uses as much as digits as its factorization.

66693643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 43.

The square root of 66693643 is about 8166.6175984920. The cubic root of 66693643 is about 405.5348174991.

The spelling of 66693643 in words is "sixty-six million, six hundred ninety-three thousand, six hundred forty-three".