381642689 has 2 divisors, whose sum is σ = 381642690. Its totient is φ = 381642688.

The previous prime is 381642661. The next prime is 381642691. The reversal of 381642689 is 986246183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 269452225 + 112190464 = 16415^2 + 10592^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-381642689 is a prime.

It is a super-2 number, since 2×381642689² = 291302284134301442, which contains 22 as substring.

Together with 381642691, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (381642619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190821344 + 190821345.

It is an arithmetic number, because the mean of its divisors is an integer number (190821345).

Almost surely, 2^381642689 is an apocalyptic number.

It is an amenable number.

381642689 is a deficient number, since it is larger than the sum of its proper divisors (1).

381642689 is an equidigital number, since it uses as much as digits as its factorization.

381642689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 497664, while the sum is 47.

The square root of 381642689 is about 19535.6773366065. The cubic root of 381642689 is about 725.3578504513.

The spelling of 381642689 in words is "three hundred eighty-one million, six hundred forty-two thousand, six hundred eighty-nine".