55718521 has 4 divisors (see below), whose sum is σ = 56007412. Its totient is φ = 55429632.

The previous prime is 55718519. The next prime is 55718543. The reversal of 55718521 is 12581755.

55718521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12581755 = 5 ⋅2516351.

It can be written as a sum of positive squares in 2 ways, for example, as 12960000 + 42758521 = 3600^2 + 6539^2 .

It is a cyclic number.

It is not a de Polignac number, because 55718521 - 2¹ = 55718519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55718561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144156 + ... + 144541.

It is an arithmetic number, because the mean of its divisors is an integer number (14001853).

Almost surely, 2^55718521 is an apocalyptic number.

It is an amenable number.

55718521 is a deficient number, since it is larger than the sum of its proper divisors (288891).

55718521 is a wasteful number, since it uses less digits than its factorization.

55718521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288890.

The product of its digits is 14000, while the sum is 34.

The square root of 55718521 is about 7464.4839741271. The cubic root of 55718521 is about 381.9441476962.

The spelling of 55718521 in words is "fifty-five million, seven hundred eighteen thousand, five hundred twenty-one".