561801905 has 12 divisors (see below), whose sum is σ = 784229940. Its totient is φ = 385235424.

The previous prime is 561801869. The next prime is 561801931. The reversal of 561801905 is 509108165.

561801905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 129868816 + 431933089 = 11396^2 + 20783^2 .

It is not a de Polignac number, because 561801905 - 2¹⁰ = 561800881 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1146290 + ... + 1146779.

It is an arithmetic number, because the mean of its divisors is an integer number (65352495).

Almost surely, 2^561801905 is an apocalyptic number.

It is an amenable number.

561801905 is a deficient number, since it is larger than the sum of its proper divisors (222428035).

561801905 is a wasteful number, since it uses less digits than its factorization.

561801905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2293088 (or 2293081 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 35.

The square root of 561801905 is about 23702.3607474024. The cubic root of 561801905 is about 825.1401806487.

It can be divided in two parts, 56180 and 1905, that added together give a palindrome (58085).

The spelling of 561801905 in words is "five hundred sixty-one million, eight hundred one thousand, nine hundred five".