52210721 has 4 divisors (see below), whose sum is σ = 52245012. Its totient is φ = 52176432.

The previous prime is 52210687. The next prime is 52210733. The reversal of 52210721 is 12701225.

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 4752400 + 47458321 = 2180^2 + 6889^2 .

It is a cyclic number.

It is not a de Polignac number, because 52210721 - 2⁶ = 52210657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 52210693 and 52210702.

It is not an unprimeable number, because it can be changed into a prime (52210751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14750 + ... + 17943.

It is an arithmetic number, because the mean of its divisors is an integer number (13061253).

Almost surely, 2^52210721 is an apocalyptic number.

It is an amenable number.

52210721 is a deficient number, since it is larger than the sum of its proper divisors (34291).

52210721 is a wasteful number, since it uses less digits than its factorization.

52210721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34290.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 52210721 is about 7225.6986513416. The cubic root of 52210721 is about 373.7546146938.

Adding to 52210721 its reverse (12701225), we get a palindrome (64911946).

The spelling of 52210721 in words is "fifty-two million, two hundred ten thousand, seven hundred twenty-one".