55338721 has 9 divisors (see below), whose sum is σ = 56984979. Its totient is φ = 53739336.

The previous prime is 55338719. The next prime is 55338733. The reversal of 55338721 is 12783355.

The square root of 55338721 is 7439.

It is a perfect power (a square), and thus also a powerful number.

55338721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 50339025 + 4999696 = 7095^2 + 2236^2 .

It is not a de Polignac number, because 55338721 - 2¹ = 55338719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55338761) 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 8 ways as a sum of consecutive naturals, for example, 319791 + ... + 319963.

Almost surely, 2^55338721 is an apocalyptic number.

55338721 is the 7439-th square number.

55338721 is the 3720-th centered octagonal number.

It is an amenable number.

55338721 is a deficient number, since it is larger than the sum of its proper divisors (1646258).

55338721 is an frugal number, since it uses more digits than its factorization.

55338721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432 (or 216 counting only the distinct ones).

The product of its digits is 25200, while the sum is 34.

The cubic root of 55338721 is about 381.0743397169.

The spelling of 55338721 in words is "fifty-five million, three hundred thirty-eight thousand, seven hundred twenty-one".