5591988 has 18 divisors (see below), whose sum is σ = 14135394. Its totient is φ = 1863984.

The previous prime is 5591987. The next prime is 5592001. The reversal of 5591988 is 8891955.

5591988 is a `hidden beast` number, since 559 + 1 + 98 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5253264 + 338724 = 2292^2 + 582^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5591987) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 77631 + ... + 77702.

Almost surely, 2^5591988 is an apocalyptic number.

It is an amenable number.

5591988 is an abundant number, since it is smaller than the sum of its proper divisors (8543406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

5591988 is a wasteful number, since it uses less digits than its factorization.

5591988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155343 (or 155338 counting only the distinct ones).

The product of its digits is 129600, while the sum is 45.

The square root of 5591988 is about 2364.7384633401. The cubic root of 5591988 is about 177.4960707984.

The spelling of 5591988 in words is "five million, five hundred ninety-one thousand, nine hundred eighty-eight".