53218621 has 4 divisors (see below), whose sum is σ = 53281152. Its totient is φ = 53156092.

The previous prime is 53218603. The next prime is 53218643. The reversal of 53218621 is 12681235.

53218621 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 53218621 - 2⁵ = 53218589 is a prime.

It is a super-2 number, since 2×53218621² = 5664443242283282, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 53218621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53218651) 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, 29971 + ... + 31696.

It is an arithmetic number, because the mean of its divisors is an integer number (13320288).

Almost surely, 2^53218621 is an apocalyptic number.

It is an amenable number.

53218621 is a deficient number, since it is larger than the sum of its proper divisors (62531).

53218621 is an equidigital number, since it uses as much as digits as its factorization.

53218621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62530.

The product of its digits is 2880, while the sum is 28.

The square root of 53218621 is about 7295.1093891730. The cubic root of 53218621 is about 376.1443467397.

Adding to 53218621 its reverse (12681235), we get a palindrome (65899856).

The spelling of 53218621 in words is "fifty-three million, two hundred eighteen thousand, six hundred twenty-one".