5515561 has 4 divisors (see below), whose sum is σ = 5755392. Its totient is φ = 5275732.

The previous prime is 5515541. The next prime is 5515579. The reversal of 5515561 is 1655155.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1655155 = 5 ⋅331031.

It is a cyclic number.

It is not a de Polignac number, because 5515561 - 2¹¹ = 5513513 is a prime.

It is a Duffinian number.

5515561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (5515501) 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, 119881 + ... + 119926.

It is an arithmetic number, because the mean of its divisors is an integer number (1438848).

Almost surely, 2^5515561 is an apocalyptic number.

It is an amenable number.

5515561 is a deficient number, since it is larger than the sum of its proper divisors (239831).

5515561 is a wasteful number, since it uses less digits than its factorization.

5515561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239830.

The product of its digits is 3750, while the sum is 28.

The square root of 5515561 is about 2348.5231529623. The cubic root of 5515561 is about 176.6837319855.

The spelling of 5515561 in words is "five million, five hundred fifteen thousand, five hundred sixty-one".