1561123 has 2 divisors, whose sum is σ = 1561124. Its totient is φ = 1561122.

The previous prime is 1561121. The next prime is 1561139. The reversal of 1561123 is 3211651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561123 - 2¹ = 1561121 is a prime.

It is a super-2 number, since 2×1561123² = 4874210042258, which contains 22 as substring.

Together with 1561121, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1561123.

It is not a weakly prime, because it can be changed into another prime (1561121) 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, 780561 + 780562.

It is an arithmetic number, because the mean of its divisors is an integer number (780562).

2^1561123 is an apocalyptic number.

1561123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561123 is an equidigital number, since it uses as much as digits as its factorization.

1561123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180, while the sum is 19.

The square root of 1561123 is about 1249.4490785942. The cubic root of 1561123 is about 116.0056229934.

Adding to 1561123 its reverse (3211651), we get a palindrome (4772774).

The spelling of 1561123 in words is "one million, five hundred sixty-one thousand, one hundred twenty-three".