66907657 has 2 divisors, whose sum is σ = 66907658. Its totient is φ = 66907656.

The previous prime is 66907651. The next prime is 66907691. The reversal of 66907657 is 75670966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 63824121 + 3083536 = 7989^2 + 1756^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66907657 is a prime.

It is not a weakly prime, because it can be changed into another prime (66907651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33453828 + 33453829.

It is an arithmetic number, because the mean of its divisors is an integer number (33453829).

Almost surely, 2^66907657 is an apocalyptic number.

It is an amenable number.

66907657 is a deficient number, since it is larger than the sum of its proper divisors (1).

66907657 is an equidigital number, since it uses as much as digits as its factorization.

66907657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 476280, while the sum is 46.

The square root of 66907657 is about 8179.7100804368. The cubic root of 66907657 is about 405.9681294597.

The spelling of 66907657 in words is "sixty-six million, nine hundred seven thousand, six hundred fifty-seven".