1556531423 has 4 divisors (see below), whose sum is σ = 1556611968. Its totient is φ = 1556450880.

The previous prime is 1556531399. The next prime is 1556531443. The reversal of 1556531423 is 3241356551.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3241356551 = 47 ⋅68965033.

It is a cyclic number.

It is not a de Polignac number, because 1556531423 - 2¹⁴ = 1556515039 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1556531443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8015 + ... + 56367.

It is an arithmetic number, because the mean of its divisors is an integer number (389152992).

Almost surely, 2^1556531423 is an apocalyptic number.

1556531423 is a deficient number, since it is larger than the sum of its proper divisors (80545).

1556531423 is an equidigital number, since it uses as much as digits as its factorization.

1556531423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80544.

The product of its digits is 54000, while the sum is 35.

The square root of 1556531423 is about 39452.9013255046. The cubic root of 1556531423 is about 1158.9177934483.

Adding to 1556531423 its reverse (3241356551), we get a palindrome (4797887974).

The spelling of 1556531423 in words is "one billion, five hundred fifty-six million, five hundred thirty-one thousand, four hundred twenty-three".