66889091 has 2 divisors, whose sum is σ = 66889092. Its totient is φ = 66889090.

The previous prime is 66889079. The next prime is 66889099. The reversal of 66889091 is 19098866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66889091 - 2²² = 62694787 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66889099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444545 + 33444546.

It is an arithmetic number, because the mean of its divisors is an integer number (33444546).

Almost surely, 2^66889091 is an apocalyptic number.

66889091 is a deficient number, since it is larger than the sum of its proper divisors (1).

66889091 is an equidigital number, since it uses as much as digits as its factorization.

66889091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 66889091 is about 8178.5751203984. The cubic root of 66889091 is about 405.9305757033.

The spelling of 66889091 in words is "sixty-six million, eight hundred eighty-nine thousand, ninety-one".