53021821 has 2 divisors, whose sum is σ = 53021822. Its totient is φ = 53021820.

The previous prime is 53021807. The next prime is 53021833. The reversal of 53021821 is 12812035.

53021821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52852900 + 168921 = 7270^2 + 411^2 .

It is a cyclic number.

It is not a de Polignac number, because 53021821 - 2⁵ = 53021789 is a prime.

It is a super-2 number, since 2×53021821² = 5622627004312082, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 53021792 and 53021801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53021621) 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 as a sum of consecutive naturals, namely, 26510910 + 26510911.

It is an arithmetic number, because the mean of its divisors is an integer number (26510911).

Almost surely, 2^53021821 is an apocalyptic number.

It is an amenable number.

53021821 is a deficient number, since it is larger than the sum of its proper divisors (1).

53021821 is an equidigital number, since it uses as much as digits as its factorization.

53021821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 53021821 is about 7281.6084074880. The cubic root of 53021821 is about 375.6801192366.

Adding to 53021821 its reverse (12812035), we get a palindrome (65833856).

The spelling of 53021821 in words is "fifty-three million, twenty-one thousand, eight hundred twenty-one".