5511981 has 8 divisors (see below), whose sum is σ = 7361280. Its totient is φ = 3668672.

The previous prime is 5511977. The next prime is 5511983. The reversal of 5511981 is 1891155.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 5511981 - 2² = 5511977 is a prime.

It is a super-2 number, since 2×5511981² = 60763869088722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5511983) 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 7 ways as a sum of consecutive naturals, for example, 1525 + ... + 3653.

It is an arithmetic number, because the mean of its divisors is an integer number (920160).

Almost surely, 2^5511981 is an apocalyptic number.

It is an amenable number.

5511981 is a deficient number, since it is larger than the sum of its proper divisors (1849299).

5511981 is a wasteful number, since it uses less digits than its factorization.

5511981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2995.

The product of its digits is 1800, while the sum is 30.

The square root of 5511981 is about 2347.7608481274. The cubic root of 5511981 is about 176.6454968502.

The spelling of 5511981 in words is "five million, five hundred eleven thousand, nine hundred eighty-one".