381643651 has 2 divisors, whose sum is σ = 381643652. Its totient is φ = 381643650.

The previous prime is 381643649. The next prime is 381643679. The reversal of 381643651 is 156346183.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 381643651 - 2¹ = 381643649 is a prime.

Together with 381643649, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 381643651.

It is not a weakly prime, because it can be changed into another prime (381643631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190821825 + 190821826.

It is an arithmetic number, because the mean of its divisors is an integer number (190821826).

Almost surely, 2^381643651 is an apocalyptic number.

381643651 is a deficient number, since it is larger than the sum of its proper divisors (1).

381643651 is an equidigital number, since it uses as much as digits as its factorization.

381643651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 37.

The square root of 381643651 is about 19535.7019582097. The cubic root of 381643651 is about 725.3584599163.

The spelling of 381643651 in words is "three hundred eighty-one million, six hundred forty-three thousand, six hundred fifty-one".