66128849 has 2 divisors, whose sum is σ = 66128850. Its totient is φ = 66128848.

The previous prime is 66128837. The next prime is 66128857. The reversal of 66128849 is 94882166.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57532225 + 8596624 = 7585^2 + 2932^2 .

It is a cyclic number.

It is not a de Polignac number, because 66128849 - 2¹² = 66124753 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66128899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33064424 + 33064425.

It is an arithmetic number, because the mean of its divisors is an integer number (33064425).

Almost surely, 2^66128849 is an apocalyptic number.

It is an amenable number.

66128849 is a deficient number, since it is larger than the sum of its proper divisors (1).

66128849 is an equidigital number, since it uses as much as digits as its factorization.

66128849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 44.

The square root of 66128849 is about 8131.9646457667. The cubic root of 66128849 is about 404.3868158245.

The spelling of 66128849 in words is "sixty-six million, one hundred twenty-eight thousand, eight hundred forty-nine".