221431033 has 2 divisors, whose sum is σ = 221431034. Its totient is φ = 221431032.

The previous prime is 221431019. The next prime is 221431039. The reversal of 221431033 is 330134122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 215120889 + 6310144 = 14667^2 + 2512^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221431033 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221431033.

It is not a weakly prime, because it can be changed into another prime (221431039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110715516 + 110715517.

It is an arithmetic number, because the mean of its divisors is an integer number (110715517).

Almost surely, 2^221431033 is an apocalyptic number.

It is an amenable number.

221431033 is a deficient number, since it is larger than the sum of its proper divisors (1).

221431033 is an equidigital number, since it uses as much as digits as its factorization.

221431033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 221431033 is about 14880.5588940738. The cubic root of 221431033 is about 604.9871663603.

Adding to 221431033 its reverse (330134122), we get a palindrome (551565155).

The spelling of 221431033 in words is "two hundred twenty-one million, four hundred thirty-one thousand, thirty-three".