66220157 has 2 divisors, whose sum is σ = 66220158. Its totient is φ = 66220156.

The previous prime is 66220153. The next prime is 66220169. The reversal of 66220157 is 75102266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65836996 + 383161 = 8114^2 + 619^2 .

It is a cyclic number.

It is not a de Polignac number, because 66220157 - 2² = 66220153 is a prime.

It is a Chen prime.

It is equal to p_3908423 and since 66220157 and 3908423 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66220153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33110078 + 33110079.

It is an arithmetic number, because the mean of its divisors is an integer number (33110079).

Almost surely, 2^66220157 is an apocalyptic number.

It is an amenable number.

66220157 is a deficient number, since it is larger than the sum of its proper divisors (1).

66220157 is an equidigital number, since it uses as much as digits as its factorization.

66220157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 66220157 is about 8137.5768506356. The cubic root of 66220157 is about 404.5728504659.

The spelling of 66220157 in words is "sixty-six million, two hundred twenty thousand, one hundred fifty-seven".