4220521 has 2 divisors, whose sum is σ = 4220522. Its totient is φ = 4220520.

The previous prime is 4220519. The next prime is 4220533. The reversal of 4220521 is 1250224.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4044121 + 176400 = 2011^2 + 420^2 .

It is a cyclic number.

It is not a de Polignac number, because 4220521 - 2¹ = 4220519 is a prime.

It is a super-2 number, since 2×4220521² = 35625595022882, which contains 22 as substring.

Together with 4220519, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 4220495 and 4220504.

It is not a weakly prime, because it can be changed into another prime (4220551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2110260 + 2110261.

It is an arithmetic number, because the mean of its divisors is an integer number (2110261).

Almost surely, 2^4220521 is an apocalyptic number.

It is an amenable number.

4220521 is a deficient number, since it is larger than the sum of its proper divisors (1).

4220521 is an equidigital number, since it uses as much as digits as its factorization.

4220521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 4220521 is about 2054.3906639196. The cubic root of 4220521 is about 161.6052089823.

Adding to 4220521 its reverse (1250224), we get a palindrome (5470745).

The spelling of 4220521 in words is "four million, two hundred twenty thousand, five hundred twenty-one".