66139357 has 2 divisors, whose sum is σ = 66139358. Its totient is φ = 66139356.

The previous prime is 66139351. The next prime is 66139373. The reversal of 66139357 is 75393166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42432196 + 23707161 = 6514^2 + 4869^2 .

It is a cyclic number.

It is not a de Polignac number, because 66139357 - 2¹⁵ = 66106589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66139351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33069678 + 33069679.

It is an arithmetic number, because the mean of its divisors is an integer number (33069679).

Almost surely, 2^66139357 is an apocalyptic number.

It is an amenable number.

66139357 is a deficient number, since it is larger than the sum of its proper divisors (1).

66139357 is an equidigital number, since it uses as much as digits as its factorization.

66139357 is an evil number, because the sum of its binary digits is even.

The product of its digits is 102060, while the sum is 40.

The square root of 66139357 is about 8132.6107124342. The cubic root of 66139357 is about 404.4082339684.

The spelling of 66139357 in words is "sixty-six million, one hundred thirty-nine thousand, three hundred fifty-seven".