561111001 has 16 divisors (see below), whose sum is σ = 627388416. Its totient is φ = 501666000.

The previous prime is 561110981. The next prime is 561111043. The reversal of 561111001 is 100111165.

It is not a de Polignac number, because 561111001 - 2⁵ = 561110969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (561111301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77736 + ... + 84646.

It is an arithmetic number, because the mean of its divisors is an integer number (39211776).

Almost surely, 2^561111001 is an apocalyptic number.

It is an amenable number.

561111001 is a deficient number, since it is larger than the sum of its proper divisors (66277415).

561111001 is an equidigital number, since it uses as much as digits as its factorization.

561111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7005 (or 6983 counting only the distinct ones).

The product of its (nonzero) digits is 30, while the sum is 16.

The square root of 561111001 is about 23687.7816817025. The cubic root of 561111001 is about 824.8017894197.

Adding to 561111001 its reverse (100111165), we get a palindrome (661222166).

The spelling of 561111001 in words is "five hundred sixty-one million, one hundred eleven thousand, one".