4551561 has 18 divisors (see below), whose sum is σ = 7648602. Its totient is φ = 2600640.

The previous prime is 4551559. The next prime is 4551571. The reversal of 4551561 is 1651554.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 3980025 + 571536 = 1995^2 + 756^2 .

It is not a de Polignac number, because 4551561 - 2¹ = 4551559 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is an Ulam number.

4551561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (4551571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4720 + ... + 5601.

Almost surely, 2^4551561 is an apocalyptic number.

It is an amenable number.

4551561 is a deficient number, since it is larger than the sum of its proper divisors (3097041).

4551561 is a wasteful number, since it uses less digits than its factorization.

4551561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10341 (or 10331 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 4551561 is about 2133.4387734360. The cubic root of 4551561 is about 165.7245273878.

It can be divided in two parts, 455 and 1561, that added together give a triangular number (2016 = T₆₃).

The spelling of 4551561 in words is "four million, five hundred fifty-one thousand, five hundred sixty-one".