55209791 has 16 divisors (see below), whose sum is σ = 70146048. Its totient is φ = 42271200.

The previous prime is 55209779. The next prime is 55209793. The reversal of 55209791 is 19790255.

It is a cyclic number.

It is not a de Polignac number, because 55209791 - 2¹⁸ = 54947647 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55209793) 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 15 ways as a sum of consecutive naturals, for example, 6965 + ... + 12606.

It is an arithmetic number, because the mean of its divisors is an integer number (4384128).

Almost surely, 2^55209791 is an apocalyptic number.

55209791 is a deficient number, since it is larger than the sum of its proper divisors (14936257).

55209791 is a wasteful number, since it uses less digits than its factorization.

55209791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19622.

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 55209791 is about 7430.3291313373. The cubic root of 55209791 is about 380.7781630098.

The spelling of 55209791 in words is "fifty-five million, two hundred nine thousand, seven hundred ninety-one".