55784909 has 4 divisors (see below), whose sum is σ = 56210880. Its totient is φ = 55358940.

The previous prime is 55784851. The next prime is 55784917. The reversal of 55784909 is 90948755.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90948755 = 5 ⋅18189751.

It is a cyclic number.

It is not a de Polignac number, because 55784909 - 2⁸ = 55784653 is a prime.

It is a super-2 number, since 2×55784909² = 6223912144276562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55784999) 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, 212789 + ... + 213050.

It is an arithmetic number, because the mean of its divisors is an integer number (14052720).

Almost surely, 2^55784909 is an apocalyptic number.

It is an amenable number.

55784909 is a deficient number, since it is larger than the sum of its proper divisors (425971).

55784909 is a wasteful number, since it uses less digits than its factorization.

55784909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425970.

The product of its (nonzero) digits is 453600, while the sum is 47.

The square root of 55784909 is about 7468.9295752470. The cubic root of 55784909 is about 382.0957815612.

The spelling of 55784909 in words is "fifty-five million, seven hundred eighty-four thousand, nine hundred nine".