5511581 has 2 divisors, whose sum is σ = 5511582. Its totient is φ = 5511580.

The previous prime is 5511547. The next prime is 5511599. The reversal of 5511581 is 1851155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4268356 + 1243225 = 2066^2 + 1115^2 .

It is a cyclic number.

It is not a de Polignac number, because 5511581 - 2¹⁸ = 5249437 is a prime.

It is a super-2 number, since 2×5511581² = 60755050239122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 5511581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5511511) 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 as a sum of consecutive naturals, namely, 2755790 + 2755791.

It is an arithmetic number, because the mean of its divisors is an integer number (2755791).

Almost surely, 2^5511581 is an apocalyptic number.

It is an amenable number.

5511581 is a deficient number, since it is larger than the sum of its proper divisors (1).

5511581 is an equidigital number, since it uses as much as digits as its factorization.

5511581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1000, while the sum is 26.

The square root of 5511581 is about 2347.6756590296. The cubic root of 5511581 is about 176.6412237400.

The spelling of 5511581 in words is "five million, five hundred eleven thousand, five hundred eighty-one".