56218109 has 4 divisors (see below), whose sum is σ = 56245116. Its totient is φ = 56191104.

The previous prime is 56218081. The next prime is 56218111. The reversal of 56218109 is 90181265.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24970009 + 31248100 = 4997^2 + 5590^2 .

It is a cyclic number.

It is not a de Polignac number, because 56218109 - 2⁸ = 56217853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56218189) 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 3 ways as a sum of consecutive naturals, for example, 10094 + ... + 14639.

It is an arithmetic number, because the mean of its divisors is an integer number (14061279).

Almost surely, 2^56218109 is an apocalyptic number.

It is an amenable number.

56218109 is a deficient number, since it is larger than the sum of its proper divisors (27007).

56218109 is a wasteful number, since it uses less digits than its factorization.

56218109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27006.

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 56218109 is about 7497.8736319039. The cubic root of 56218109 is about 383.0822925108.

The spelling of 56218109 in words is "fifty-six million, two hundred eighteen thousand, one hundred nine".