66888989801 has 2 divisors, whose sum is σ = 66888989802. Its totient is φ = 66888989800.

The previous prime is 66888989779. The next prime is 66888989899. The reversal of 66888989801 is 10898988866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65255213401 + 1633776400 = 255451^2 + 40420^2 .

It is a cyclic number.

It is not a de Polignac number, because 66888989801 - 2¹⁸ = 66888727657 is a prime.

It is not a weakly prime, because it can be changed into another prime (66888889801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444494900 + 33444494901.

It is an arithmetic number, because the mean of its divisors is an integer number (33444494901).

Almost surely, 2^66888989801 is an apocalyptic number.

It is an amenable number.

66888989801 is a deficient number, since it is larger than the sum of its proper divisors (1).

66888989801 is an equidigital number, since it uses as much as digits as its factorization.

66888989801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 95551488, while the sum is 71.

The spelling of 66888989801 in words is "sixty-six billion, eight hundred eighty-eight million, nine hundred eighty-nine thousand, eight hundred one".