381603781 has 4 divisors (see below), whose sum is σ = 410957932. Its totient is φ = 352249632.

The previous prime is 381603713. The next prime is 381603791. The reversal of 381603781 is 187306183.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 144720900 + 236882881 = 12030^2 + 15391^2 .

It is a cyclic number.

It is not a de Polignac number, because 381603781 - 2¹⁵ = 381571013 is a prime.

It is a super-2 number, since 2×381603781² = 291242891346991922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 381603781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381603791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14677056 + ... + 14677081.

It is an arithmetic number, because the mean of its divisors is an integer number (102739483).

Almost surely, 2^381603781 is an apocalyptic number.

It is an amenable number.

381603781 is a deficient number, since it is larger than the sum of its proper divisors (29354151).

381603781 is a wasteful number, since it uses less digits than its factorization.

381603781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29354150.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 381603781 is about 19534.6814921565. The cubic root of 381603781 is about 725.3331998350. Note that the first 3 decimals are identical.

The spelling of 381603781 in words is "three hundred eighty-one million, six hundred three thousand, seven hundred eighty-one".