381573781 has 2 divisors, whose sum is σ = 381573782. Its totient is φ = 381573780.

The previous prime is 381573743. The next prime is 381573799. The reversal of 381573781 is 187375183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 381420900 + 152881 = 19530^2 + 391^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-381573781 is a prime.

It is a super-2 number, since 2×381573781² = 291197100693271922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381573481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190786890 + 190786891.

It is an arithmetic number, because the mean of its divisors is an integer number (190786891).

Almost surely, 2^381573781 is an apocalyptic number.

It is an amenable number.

381573781 is a deficient number, since it is larger than the sum of its proper divisors (1).

381573781 is an equidigital number, since it uses as much as digits as its factorization.

381573781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 141120, while the sum is 43.

The square root of 381573781 is about 19533.9136119724. The cubic root of 381573781 is about 725.3141918418.

The spelling of 381573781 in words is "three hundred eighty-one million, five hundred seventy-three thousand, seven hundred eighty-one".