221323997 has 2 divisors, whose sum is σ = 221323998. Its totient is φ = 221323996.

The previous prime is 221323957. The next prime is 221324021. The reversal of 221323997 is 799323122.

221323997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 220997956 + 326041 = 14866^2 + 571^2 .

It is a cyclic number.

It is not a de Polignac number, because 221323997 - 2⁸ = 221323741 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221323997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221323937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110661998 + 110661999.

It is an arithmetic number, because the mean of its divisors is an integer number (110661999).

Almost surely, 2^221323997 is an apocalyptic number.

It is an amenable number.

221323997 is a deficient number, since it is larger than the sum of its proper divisors (1).

221323997 is an equidigital number, since it uses as much as digits as its factorization.

221323997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 221323997 is about 14876.9619546465. The cubic root of 221323997 is about 604.8896704761.

The spelling of 221323997 in words is "two hundred twenty-one million, three hundred twenty-three thousand, nine hundred ninety-seven".