53955721 has 4 divisors (see below), whose sum is σ = 53972244. Its totient is φ = 53939200.

The previous prime is 53955691. The next prime is 53955743. The reversal of 53955721 is 12755935.

It is a happy number.

53955721 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.

It can be written as a sum of positive squares in 2 ways, for example, as 38440000 + 15515721 = 6200^2 + 3939^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-53955721 is a prime.

It is a super-2 number, since 2×53955721² = 5822439657259682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (53955761) 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, 1540 + ... + 10501.

It is an arithmetic number, because the mean of its divisors is an integer number (13493061).

Almost surely, 2^53955721 is an apocalyptic number.

It is an amenable number.

53955721 is a deficient number, since it is larger than the sum of its proper divisors (16523).

53955721 is a wasteful number, since it uses less digits than its factorization.

53955721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16522.

The product of its digits is 47250, while the sum is 37.

The square root of 53955721 is about 7345.4558061430. The cubic root of 53955721 is about 377.8729755249.

The spelling of 53955721 in words is "fifty-three million, nine hundred fifty-five thousand, seven hundred twenty-one".