221404031 has 2 divisors, whose sum is σ = 221404032. Its totient is φ = 221404030.

The previous prime is 221404021. The next prime is 221404037. The reversal of 221404031 is 130404122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221404031 - 2¹⁸ = 221141887 is a prime.

It is a super-2 number, since 2×221404031² = 98039489886097922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221404037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110702015 + 110702016.

It is an arithmetic number, because the mean of its divisors is an integer number (110702016).

Almost surely, 2^221404031 is an apocalyptic number.

221404031 is a deficient number, since it is larger than the sum of its proper divisors (1).

221404031 is an equidigital number, since it uses as much as digits as its factorization.

221404031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221404031 is about 14879.6515752218. The cubic root of 221404031 is about 604.9625740116.

Adding to 221404031 its reverse (130404122), we get a palindrome (351808153).

Subtracting from 221404031 its reverse (130404122), we obtain a palindrome (90999909).

The spelling of 221404031 in words is "two hundred twenty-one million, four hundred four thousand, thirty-one".