561173539 has 2 divisors, whose sum is σ = 561173540. Its totient is φ = 561173538.

The previous prime is 561173497. The next prime is 561173549. The reversal of 561173539 is 935371165.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 561173539 - 2¹¹ = 561171491 is a prime.

It is not a weakly prime, because it can be changed into another prime (561173549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280586769 + 280586770.

It is an arithmetic number, because the mean of its divisors is an integer number (280586770).

Almost surely, 2^561173539 is an apocalyptic number.

561173539 is a deficient number, since it is larger than the sum of its proper divisors (1).

561173539 is an equidigital number, since it uses as much as digits as its factorization.

561173539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 85050, while the sum is 40.

The square root of 561173539 is about 23689.1016925505. The cubic root of 561173539 is about 824.8324307355.

It can be divided in two parts, 561 and 173539, that multiplied together give a palindrome (97355379).

The spelling of 561173539 in words is "five hundred sixty-one million, one hundred seventy-three thousand, five hundred thirty-nine".