1257491 has 2 divisors, whose sum is σ = 1257492. Its totient is φ = 1257490.

The previous prime is 1257463. The next prime is 1257493. The reversal of 1257491 is 1947521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1257491 - 2¹⁸ = 995347 is a prime.

Together with 1257493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1257493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628745 + 628746.

It is an arithmetic number, because the mean of its divisors is an integer number (628746).

2^1257491 is an apocalyptic number.

1257491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1257491 is an equidigital number, since it uses as much as digits as its factorization.

1257491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 29.

The square root of 1257491 is about 1121.3790616915. The cubic root of 1257491 is about 107.9364910104.

The spelling of 1257491 in words is "one million, two hundred fifty-seven thousand, four hundred ninety-one".