1556161042 has 4 divisors (see below), whose sum is σ = 2334241566. Its totient is φ = 778080520.

The previous prime is 1556161021. The next prime is 1556161043. The reversal of 1556161042 is 2401616551.

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

It can be written as a sum of positive squares in only one way, i.e., 1352841961 + 203319081 = 36781^2 + 14259^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1556160995 and 1556161013.

It is not an unprimeable number, because it can be changed into a prime (1556161043) 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 as a sum of consecutive naturals, namely, 389040259 + ... + 389040262.

Almost surely, 2^1556161042 is an apocalyptic number.

1556161042 is a deficient number, since it is larger than the sum of its proper divisors (778080524).

1556161042 is an equidigital number, since it uses as much as digits as its factorization.

1556161042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778080523.

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 1556161042 is about 39448.2070821983. The cubic root of 1556161042 is about 1158.8258635809.

Adding to 1556161042 its reverse (2401616551), we get a palindrome (3957777593).

The spelling of 1556161042 in words is "one billion, five hundred fifty-six million, one hundred sixty-one thousand, forty-two".