5661551 has 4 divisors (see below), whose sum is σ = 6470352. Its totient is φ = 4852752.

The previous prime is 5661547. The next prime is 5661559. The reversal of 5661551 is 1551665.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1551665 = 5 ⋅310333.

It is a cyclic number.

It is not a de Polignac number, because 5661551 - 2² = 5661547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5661559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 404390 + ... + 404403.

It is an arithmetic number, because the mean of its divisors is an integer number (1617588).

Almost surely, 2^5661551 is an apocalyptic number.

5661551 is a deficient number, since it is larger than the sum of its proper divisors (808801).

5661551 is an equidigital number, since it uses as much as digits as its factorization.

5661551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 808800.

The product of its digits is 4500, while the sum is 29.

The square root of 5661551 is about 2379.4013953093. The cubic root of 5661551 is about 178.2290427769.

The spelling of 5661551 in words is "five million, six hundred sixty-one thousand, five hundred fifty-one".