221020403 has 2 divisors, whose sum is σ = 221020404. Its totient is φ = 221020402.

The previous prime is 221020399. The next prime is 221020447. The reversal of 221020403 is 304020122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221020403 - 2² = 221020399 is a prime.

It is not a weakly prime, because it can be changed into another prime (221020493) 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, 110510201 + 110510202.

It is an arithmetic number, because the mean of its divisors is an integer number (110510202).

Almost surely, 2^221020403 is an apocalyptic number.

221020403 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020403 is an equidigital number, since it uses as much as digits as its factorization.

221020403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 221020403 is about 14866.7549586317. The cubic root of 221020403 is about 604.6129646678.

Adding to 221020403 its reverse (304020122), we get a palindrome (525040525).

The spelling of 221020403 in words is "two hundred twenty-one million, twenty thousand, four hundred three".