2211561 has 24 divisors (see below), whose sum is σ = 3538080. Its totient is φ = 1320000.

The previous prime is 2211557. The next prime is 2211563. The reversal of 2211561 is 1651122.

It is not a de Polignac number, because 2211561 - 2² = 2211557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2211563) 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 in 23 ways as a sum of consecutive naturals, for example, 8686 + ... + 8936.

It is an arithmetic number, because the mean of its divisors is an integer number (147420).

2^2211561 is an apocalyptic number.

It is an amenable number.

2211561 is a deficient number, since it is larger than the sum of its proper divisors (1326519).

2211561 is a wasteful number, since it uses less digits than its factorization.

2211561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 354 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 2211561 is about 1487.1318031701. The cubic root of 2211561 is about 130.2865670494.

Adding to 2211561 its reverse (1651122), we get a palindrome (3862683).

It can be divided in two parts, 2211 and 561, that added together give a palindrome (2772).

The spelling of 2211561 in words is "two million, two hundred eleven thousand, five hundred sixty-one".