391057 has 2 divisors, whose sum is σ = 391058. Its totient is φ = 391056.

The previous prime is 391049. The next prime is 391063. The reversal of 391057 is 750193.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 389376 + 1681 = 624^2 + 41^2 .

It is a cyclic number.

It is not a de Polignac number, because 391057 - 2³ = 391049 is a prime.

391057 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195528 + 195529.

It is an arithmetic number, because the mean of its divisors is an integer number (195529).

2³⁹¹⁰⁵⁷ is an apocalyptic number.

It is an amenable number.

391057 is a deficient number, since it is larger than the sum of its proper divisors (1).

391057 is an equidigital number, since it uses as much as digits as its factorization.

391057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 945, while the sum is 25.

The square root of 391057 is about 625.3455045013. The cubic root of 391057 is about 73.1273812749.

The spelling of 391057 in words is "three hundred ninety-one thousand, fifty-seven".