66290381 has 2 divisors, whose sum is σ = 66290382. Its totient is φ = 66290380.

The previous prime is 66290339. The next prime is 66290407. The reversal of 66290381 is 18309266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49928356 + 16362025 = 7066^2 + 4045^2 .

It is a cyclic number.

It is not a de Polignac number, because 66290381 - 2¹⁴ = 66273997 is a prime.

It is a super-2 number, since 2×66290381² = 8788829226250322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66290281) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33145190 + 33145191.

It is an arithmetic number, because the mean of its divisors is an integer number (33145191).

Almost surely, 2^66290381 is an apocalyptic number.

It is an amenable number.

66290381 is a deficient number, since it is larger than the sum of its proper divisors (1).

66290381 is an equidigital number, since it uses as much as digits as its factorization.

66290381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 66290381 is about 8141.8905052819. The cubic root of 66290381 is about 404.7158114022.

The spelling of 66290381 in words is "sixty-six million, two hundred ninety thousand, three hundred eighty-one".