561100121 has 4 divisors (see below), whose sum is σ = 562272000. Its totient is φ = 559928244.

The previous prime is 561100109. The next prime is 561100139. The reversal of 561100121 is 121001165.

561100121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561100121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561100121.

It is not an unprimeable number, because it can be changed into a prime (561100721) 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, 585221 + ... + 586178.

It is an arithmetic number, because the mean of its divisors is an integer number (140568000).

Almost surely, 2^561100121 is an apocalyptic number.

It is an amenable number.

561100121 is a deficient number, since it is larger than the sum of its proper divisors (1171879).

561100121 is a wasteful number, since it uses less digits than its factorization.

561100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1171878.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 561100121 is about 23687.5520263281. The cubic root of 561100121 is about 824.7964583881.

Adding to 561100121 its reverse (121001165), we get a palindrome (682101286).

The spelling of 561100121 in words is "five hundred sixty-one million, one hundred thousand, one hundred twenty-one".