381257557 has 2 divisors, whose sum is σ = 381257558. Its totient is φ = 381257556.

The previous prime is 381257551. The next prime is 381257599. The reversal of 381257557 is 755752183.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 219306481 + 161951076 = 14809^2 + 12726^2 .

It is a cyclic number.

It is not a de Polignac number, because 381257557 - 2³ = 381257549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (381257551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190628778 + 190628779.

It is an arithmetic number, because the mean of its divisors is an integer number (190628779).

Almost surely, 2^381257557 is an apocalyptic number.

It is an amenable number.

381257557 is a deficient number, since it is larger than the sum of its proper divisors (1).

381257557 is an equidigital number, since it uses as much as digits as its factorization.

381257557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 294000, while the sum is 43.

The square root of 381257557 is about 19525.8177037480. The cubic root of 381257557 is about 725.1137717608.

The spelling of 381257557 in words is "three hundred eighty-one million, two hundred fifty-seven thousand, five hundred fifty-seven".