55491309 has 6 divisors (see below), whose sum is σ = 80154126. Its totient is φ = 36994200.

The previous prime is 55491301. The next prime is 55491311. The reversal of 55491309 is 90319455.

It can be written as a sum of positive squares in only one way, i.e., 53978409 + 1512900 = 7347^2 + 1230^2 .

It is not a de Polignac number, because 55491309 - 2³ = 55491301 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55491301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3082842 + ... + 3082859.

It is an arithmetic number, because the mean of its divisors is an integer number (13359021).

Almost surely, 2^55491309 is an apocalyptic number.

It is an amenable number.

55491309 is a deficient number, since it is larger than the sum of its proper divisors (24662817).

55491309 is a wasteful number, since it uses less digits than its factorization.

55491309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6165707 (or 6165704 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 55491309 is about 7449.2488883108. The cubic root of 55491309 is about 381.4242695543.

The spelling of 55491309 in words is "fifty-five million, four hundred ninety-one thousand, three hundred nine".