66428657 has 2 divisors, whose sum is σ = 66428658. Its totient is φ = 66428656.

The previous prime is 66428627. The next prime is 66428699. The reversal of 66428657 is 75682466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60357361 + 6071296 = 7769^2 + 2464^2 .

It is a cyclic number.

It is not a de Polignac number, because 66428657 - 2¹⁴ = 66412273 is a prime.

It is not a weakly prime, because it can be changed into another prime (66428627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33214328 + 33214329.

It is an arithmetic number, because the mean of its divisors is an integer number (33214329).

Almost surely, 2^66428657 is an apocalyptic number.

It is an amenable number.

66428657 is a deficient number, since it is larger than the sum of its proper divisors (1).

66428657 is an equidigital number, since it uses as much as digits as its factorization.

66428657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 44.

The square root of 66428657 is about 8150.3777213084. The cubic root of 66428657 is about 404.9970166930.

The spelling of 66428657 in words is "sixty-six million, four hundred twenty-eight thousand, six hundred fifty-seven".