55809439 has 4 divisors (see below), whose sum is σ = 63782224. Its totient is φ = 47836656.

The previous prime is 55809437. The next prime is 55809443. The reversal of 55809439 is 93490855.

It is a happy number.

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

It is not a de Polignac number, because 55809439 - 2¹ = 55809437 is a prime.

It is a super-2 number, since 2×55809439² = 6229386962989442, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55809395 and 55809404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55809433) 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, 3986382 + ... + 3986395.

It is an arithmetic number, because the mean of its divisors is an integer number (15945556).

Almost surely, 2^55809439 is an apocalyptic number.

55809439 is a deficient number, since it is larger than the sum of its proper divisors (7972785).

55809439 is an equidigital number, since it uses as much as digits as its factorization.

55809439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7972784.

The product of its (nonzero) digits is 194400, while the sum is 43.

The square root of 55809439 is about 7470.5715310142. The cubic root of 55809439 is about 382.1517789997.

The spelling of 55809439 in words is "fifty-five million, eight hundred nine thousand, four hundred thirty-nine".