5991561 has 12 divisors (see below), whose sum is σ = 8678592. Its totient is φ = 3983256.

The previous prime is 5991553. The next prime is 5991563. The reversal of 5991561 is 1651995.

5991561 is a `hidden beast` number, since 5 + 9 + 91 + 561 = 666.

5991561 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 5991561 - 2³ = 5991553 is a prime.

5991561 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5991563) 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, 3700 + ... + 5066.

It is an arithmetic number, because the mean of its divisors is an integer number (723216).

Almost surely, 2^5991561 is an apocalyptic number.

It is an amenable number.

5991561 is a deficient number, since it is larger than the sum of its proper divisors (2687031).

5991561 is a wasteful number, since it uses less digits than its factorization.

5991561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1860 (or 1857 counting only the distinct ones).

The product of its digits is 12150, while the sum is 36.

The square root of 5991561 is about 2447.7665329847. The cubic root of 5991561 is about 181.6268266404.

The spelling of 5991561 in words is "five million, nine hundred ninety-one thousand, five hundred sixty-one".