1556431 has 2 divisors, whose sum is σ = 1556432. Its totient is φ = 1556430.

The previous prime is 1556413. The next prime is 1556441. The reversal of 1556431 is 1346551.

Together with previous prime (1556413) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1556431 - 2⁹ = 1555919 is a prime.

It is a super-2 number, since 2×1556431² = 4844954915522, which contains 22 as substring.

1556431 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 1556396 and 1556405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1556441) 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, 778215 + 778216.

It is an arithmetic number, because the mean of its divisors is an integer number (778216).

2^1556431 is an apocalyptic number.

1556431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1556431 is an equidigital number, since it uses as much as digits as its factorization.

1556431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1800, while the sum is 25.

The square root of 1556431 is about 1247.5700381141. The cubic root of 1556431 is about 115.8892869548.

The spelling of 1556431 in words is "one million, five hundred fifty-six thousand, four hundred thirty-one".