66889157 has 2 divisors, whose sum is σ = 66889158. Its totient is φ = 66889156.

The previous prime is 66889117. The next prime is 66889189. The reversal of 66889157 is 75198866.

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., 44742721 + 22146436 = 6689^2 + 4706^2 .

It is a cyclic number.

It is not a de Polignac number, because 66889157 - 2¹⁶ = 66823621 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 (66889117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33444578 + 33444579.

It is an arithmetic number, because the mean of its divisors is an integer number (33444579).

Almost surely, 2^66889157 is an apocalyptic number.

It is an amenable number.

66889157 is a deficient number, since it is larger than the sum of its proper divisors (1).

66889157 is an equidigital number, since it uses as much as digits as its factorization.

66889157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 725760, while the sum is 50.

The square root of 66889157 is about 8178.5791553301. The cubic root of 66889157 is about 405.9307092149.

The spelling of 66889157 in words is "sixty-six million, eight hundred eighty-nine thousand, one hundred fifty-seven".