381406657 has 2 divisors, whose sum is σ = 381406658. Its totient is φ = 381406656.

The previous prime is 381406607. The next prime is 381406667. The reversal of 381406657 is 756604183.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 374770881 + 6635776 = 19359^2 + 2576^2 .

It is a cyclic number.

It is not a de Polignac number, because 381406657 - 2²³ = 373018049 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (381406607) 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, 190703328 + 190703329.

It is an arithmetic number, because the mean of its divisors is an integer number (190703329).

Almost surely, 2^381406657 is an apocalyptic number.

It is an amenable number.

381406657 is a deficient number, since it is larger than the sum of its proper divisors (1).

381406657 is an equidigital number, since it uses as much as digits as its factorization.

381406657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 40.

The square root of 381406657 is about 19529.6353524586. The cubic root of 381406657 is about 725.2082838746.

The spelling of 381406657 in words is "three hundred eighty-one million, four hundred six thousand, six hundred fifty-seven".