5661387 has 16 divisors (see below), whose sum is σ = 8426880. Its totient is φ = 3756456.

The previous prime is 5661367. The next prime is 5661389. The reversal of 5661387 is 7831665.

5661387 is a `hidden beast` number, since 566 + 13 + 87 = 666.

It is not a de Polignac number, because 5661387 - 2¹⁰ = 5660363 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (5661389) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7948 + ... + 8630.

It is an arithmetic number, because the mean of its divisors is an integer number (526680).

Almost surely, 2^5661387 is an apocalyptic number.

5661387 is a deficient number, since it is larger than the sum of its proper divisors (2765493).

5661387 is a wasteful number, since it uses less digits than its factorization.

5661387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999 (or 993 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 5661387 is about 2379.3669326104. The cubic root of 5661387 is about 178.2273218206.

It can be divided in two parts, 566 and 1387, that added together give a triangular number (1953 = T₆₂).

The spelling of 5661387 in words is "five million, six hundred sixty-one thousand, three hundred eighty-seven".