55361891 has 4 divisors (see below), whose sum is σ = 59620512. Its totient is φ = 51103272.

The previous prime is 55361881. The next prime is 55361909. The reversal of 55361891 is 19816355.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 55361891 - 2¹⁰ = 55360867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55361881) 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, 2129291 + ... + 2129316.

It is an arithmetic number, because the mean of its divisors is an integer number (14905128).

Almost surely, 2^55361891 is an apocalyptic number.

55361891 is a deficient number, since it is larger than the sum of its proper divisors (4258621).

55361891 is a wasteful number, since it uses less digits than its factorization.

55361891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4258620.

The product of its digits is 32400, while the sum is 38.

The square root of 55361891 is about 7440.5571699974. The cubic root of 55361891 is about 381.1275168310.

The spelling of 55361891 in words is "fifty-five million, three hundred sixty-one thousand, eight hundred ninety-one".