381956591 has 2 divisors, whose sum is σ = 381956592. Its totient is φ = 381956590.

The previous prime is 381956567. The next prime is 381956599. The reversal of 381956591 is 195659183.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 381956591 - 2¹⁸ = 381694447 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381956599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190978295 + 190978296.

It is an arithmetic number, because the mean of its divisors is an integer number (190978296).

Almost surely, 2^381956591 is an apocalyptic number.

381956591 is a deficient number, since it is larger than the sum of its proper divisors (1).

381956591 is an equidigital number, since it uses as much as digits as its factorization.

381956591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 291600, while the sum is 47.

The square root of 381956591 is about 19543.7097553151. The cubic root of 381956591 is about 725.5566654594.

The spelling of 381956591 in words is "three hundred eighty-one million, nine hundred fifty-six thousand, five hundred ninety-one".