5551891 has 4 divisors (see below), whose sum is σ = 5572800. Its totient is φ = 5530984.

The previous prime is 5551879. The next prime is 5551919. The reversal of 5551891 is 1981555.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1981555 = 5 ⋅396311.

It is a cyclic number.

It is not a de Polignac number, because 5551891 - 2¹⁵ = 5519123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5551801) 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, 10051 + ... + 10588.

It is an arithmetic number, because the mean of its divisors is an integer number (1393200).

Almost surely, 2^5551891 is an apocalyptic number.

5551891 is a deficient number, since it is larger than the sum of its proper divisors (20909).

5551891 is a wasteful number, since it uses less digits than its factorization.

5551891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20908.

The product of its digits is 9000, while the sum is 34.

The square root of 5551891 is about 2356.2451060957. The cubic root of 5551891 is about 177.0708112514.

The spelling of 5551891 in words is "five million, five hundred fifty-one thousand, eight hundred ninety-one".