55243421 has 4 divisors (see below), whose sum is σ = 58493052. Its totient is φ = 51993792.

The previous prime is 55243403. The next prime is 55243423. The reversal of 55243421 is 12434255.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17556100 + 37687321 = 4190^2 + 6139^2 .

It is a cyclic number.

It is not a de Polignac number, because 55243421 - 2¹⁴ = 55227037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55243423) 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, 1624790 + ... + 1624823.

It is an arithmetic number, because the mean of its divisors is an integer number (14623263).

Almost surely, 2^55243421 is an apocalyptic number.

It is an amenable number.

55243421 is a deficient number, since it is larger than the sum of its proper divisors (3249631).

55243421 is a wasteful number, since it uses less digits than its factorization.

55243421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3249630.

The product of its digits is 4800, while the sum is 26.

The square root of 55243421 is about 7432.5918090529. The cubic root of 55243421 is about 380.8554619223.

Adding to 55243421 its reverse (12434255), we get a palindrome (67677676).

The spelling of 55243421 in words is "fifty-five million, two hundred forty-three thousand, four hundred twenty-one".