55390209 has 16 divisors (see below), whose sum is σ = 84645888. Its totient is φ = 31560912.

The previous prime is 55390189. The next prime is 55390213. The reversal of 55390209 is 90209355.

It is not a de Polignac number, because 55390209 - 2⁵ = 55390177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 55390209.

It is not an unprimeable number, because it can be changed into a prime (55390219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4114 + ... + 11300.

It is an arithmetic number, because the mean of its divisors is an integer number (5290368).

Almost surely, 2^55390209 is an apocalyptic number.

It is an amenable number.

55390209 is a deficient number, since it is larger than the sum of its proper divisors (29255679).

55390209 is a wasteful number, since it uses less digits than its factorization.

55390209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7564.

The product of its (nonzero) digits is 12150, while the sum is 33.

The square root of 55390209 is about 7442.4598756056. The cubic root of 55390209 is about 381.1924888973.

The spelling of 55390209 in words is "fifty-five million, three hundred ninety thousand, two hundred nine".