221424997 has 2 divisors, whose sum is σ = 221424998. Its totient is φ = 221424996.

The previous prime is 221424991. The next prime is 221425021. The reversal of 221424997 is 799424122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 190053796 + 31371201 = 13786^2 + 5601^2 .

It is a cyclic number.

It is not a de Polignac number, because 221424997 - 2³ = 221424989 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221424991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110712498 + 110712499.

It is an arithmetic number, because the mean of its divisors is an integer number (110712499).

Almost surely, 2^221424997 is an apocalyptic number.

It is an amenable number.

221424997 is a deficient number, since it is larger than the sum of its proper divisors (1).

221424997 is an equidigital number, since it uses as much as digits as its factorization.

221424997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72576, while the sum is 40.

The square root of 221424997 is about 14880.3560777288. The cubic root of 221424997 is about 604.9816691848.

The spelling of 221424997 in words is "two hundred twenty-one million, four hundred twenty-four thousand, nine hundred ninety-seven".