55387809 has 24 divisors (see below), whose sum is σ = 82555200. Its totient is φ = 35766432.

The previous prime is 55387799. The next prime is 55387811. The reversal of 55387809 is 90878355.

It is not a de Polignac number, because 55387809 - 2⁵ = 55387777 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (55387859) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 38892 + ... + 40290.

It is an arithmetic number, because the mean of its divisors is an integer number (3439800).

Almost surely, 2^55387809 is an apocalyptic number.

It is an amenable number.

55387809 is a deficient number, since it is larger than the sum of its proper divisors (27167391).

55387809 is a wasteful number, since it uses less digits than its factorization.

55387809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1541 (or 1538 counting only the distinct ones).

The product of its (nonzero) digits is 302400, while the sum is 45.

The square root of 55387809 is about 7442.2986368460. The cubic root of 55387809 is about 381.1869832601.

The spelling of 55387809 in words is "fifty-five million, three hundred eighty-seven thousand, eight hundred nine".