5691987 has 18 divisors (see below), whose sum is σ = 9564828. Its totient is φ = 3252312.

The previous prime is 5691977. The next prime is 5692007. The reversal of 5691987 is 7891965.

5691987 is a `hidden beast` number, since 569 + 1 + 9 + 87 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-5691987 is a prime.

5691987 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (5691947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 6013 + ... + 6894.

Almost surely, 2^5691987 is an apocalyptic number.

5691987 is a deficient number, since it is larger than the sum of its proper divisors (3872841).

5691987 is a wasteful number, since it uses less digits than its factorization.

5691987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12927 (or 12917 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 5691987 is about 2385.7885488869. The cubic root of 5691987 is about 178.5478533753.

It can be divided in two parts, 569 and 1987, that added together give a triangular number (2556 = T₇₁).

The spelling of 5691987 in words is "five million, six hundred ninety-one thousand, nine hundred eighty-seven".