1257631 has 4 divisors (see below), whose sum is σ = 1260792. Its totient is φ = 1254472.

The previous prime is 1257611. The next prime is 1257647. The reversal of 1257631 is 1367521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1257631 - 2⁹ = 1257119 is a prime.

It is a super-2 number, since 2×1257631² = 3163271464322, which contains 22 as substring.

It is a Duffinian number.

1257631 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1257596 and 1257605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1257611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880 + ... + 1813.

It is an arithmetic number, because the mean of its divisors is an integer number (315198).

2^1257631 is an apocalyptic number.

1257631 is a deficient number, since it is larger than the sum of its proper divisors (3161).

1257631 is an equidigital number, since it uses as much as digits as its factorization.

1257631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3160.

The product of its digits is 1260, while the sum is 25.

The square root of 1257631 is about 1121.4414830922. The cubic root of 1257631 is about 107.9404964859.

The spelling of 1257631 in words is "one million, two hundred fifty-seven thousand, six hundred thirty-one".