66889477 has 2 divisors, whose sum is σ = 66889478. Its totient is φ = 66889476.

The previous prime is 66889469. The next prime is 66889483. The reversal of 66889477 is 77498866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60202081 + 6687396 = 7759^2 + 2586^2 .

It is a cyclic number.

It is not a de Polignac number, because 66889477 - 2³ = 66889469 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66889447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444738 + 33444739.

It is an arithmetic number, because the mean of its divisors is an integer number (33444739).

Almost surely, 2^66889477 is an apocalyptic number.

It is an amenable number.

66889477 is a deficient number, since it is larger than the sum of its proper divisors (1).

66889477 is an equidigital number, since it uses as much as digits as its factorization.

66889477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4064256, while the sum is 55.

The square root of 66889477 is about 8178.5987186070. The cubic root of 66889477 is about 405.9313565427.

The spelling of 66889477 in words is "sixty-six million, eight hundred eighty-nine thousand, four hundred seventy-seven".