220999997 has 2 divisors, whose sum is σ = 220999998. Its totient is φ = 220999996.

The previous prime is 220999979. The next prime is 221000027. The reversal of 220999997 is 799999022.

220999997 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (220999979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208686916 + 12313081 = 14446^2 + 3509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220999997 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 (220999957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110499998 + 110499999.

It is an arithmetic number, because the mean of its divisors is an integer number (110499999).

Almost surely, 2^220999997 is an apocalyptic number.

It is an amenable number.

220999997 is a deficient number, since it is larger than the sum of its proper divisors (1).

220999997 is an equidigital number, since it uses as much as digits as its factorization.

220999997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1653372, while the sum is 56.

The square root of 220999997 is about 14866.0686464176. The cubic root of 220999997 is about 604.5943568655.

The spelling of 220999997 in words is "two hundred twenty million, nine hundred ninety-nine thousand, nine hundred ninety-seven".