66519157 has 2 divisors, whose sum is σ = 66519158. Its totient is φ = 66519156.

The previous prime is 66519143. The next prime is 66519169. The reversal of 66519157 is 75191566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65950641 + 568516 = 8121^2 + 754^2 .

It is a cyclic number.

It is not a de Polignac number, because 66519157 - 2¹⁵ = 66486389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66519107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33259578 + 33259579.

It is an arithmetic number, because the mean of its divisors is an integer number (33259579).

Almost surely, 2^66519157 is an apocalyptic number.

It is an amenable number.

66519157 is a deficient number, since it is larger than the sum of its proper divisors (1).

66519157 is an equidigital number, since it uses as much as digits as its factorization.

66519157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56700, while the sum is 40.

The square root of 66519157 is about 8155.9277216022. The cubic root of 66519157 is about 405.1808509983.

The spelling of 66519157 in words is "sixty-six million, five hundred nineteen thousand, one hundred fifty-seven".