381661603 has 2 divisors, whose sum is σ = 381661604. Its totient is φ = 381661602.

The previous prime is 381661597. The next prime is 381661649. The reversal of 381661603 is 306166183.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 381661603 - 2⁵ = 381661571 is a prime.

It is not a weakly prime, because it can be changed into another prime (381661673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190830801 + 190830802.

It is an arithmetic number, because the mean of its divisors is an integer number (190830802).

Almost surely, 2^381661603 is an apocalyptic number.

381661603 is a deficient number, since it is larger than the sum of its proper divisors (1).

381661603 is an equidigital number, since it uses as much as digits as its factorization.

381661603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 381661603 is about 19536.1614192758. The cubic root of 381661603 is about 725.3698330309.

The spelling of 381661603 in words is "three hundred eighty-one million, six hundred sixty-one thousand, six hundred three".