5515991 has 12 divisors (see below), whose sum is σ = 6043392. Its totient is φ = 5031936.

The previous prime is 5515981. The next prime is 5516009. The reversal of 5515991 is 1995155.

It is a happy number.

It is not a de Polignac number, because 5515991 - 2⁶ = 5515927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5515921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21335 + ... + 21591.

It is an arithmetic number, because the mean of its divisors is an integer number (503616).

Almost surely, 2^5515991 is an apocalyptic number.

5515991 is a deficient number, since it is larger than the sum of its proper divisors (527401).

5515991 is a wasteful number, since it uses less digits than its factorization.

5515991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410 (or 397 counting only the distinct ones).

The product of its digits is 10125, while the sum is 35.

The square root of 5515991 is about 2348.6146980720. The cubic root of 5515991 is about 176.6883233607.

The spelling of 5515991 in words is "five million, five hundred fifteen thousand, nine hundred ninety-one".