221702749 has 2 divisors, whose sum is σ = 221702750. Its totient is φ = 221702748.

The previous prime is 221702717. The next prime is 221702753. The reversal of 221702749 is 947207122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128097124 + 93605625 = 11318^2 + 9675^2 .

It is a cyclic number.

It is not a de Polignac number, because 221702749 - 2⁵ = 221702717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221708749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110851374 + 110851375.

It is an arithmetic number, because the mean of its divisors is an integer number (110851375).

Almost surely, 2^221702749 is an apocalyptic number.

It is an amenable number.

221702749 is a deficient number, since it is larger than the sum of its proper divisors (1).

221702749 is an equidigital number, since it uses as much as digits as its factorization.

221702749 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 221702749 is about 14889.6859940027. The cubic root of 221702749 is about 605.2345232885.

The spelling of 221702749 in words is "two hundred twenty-one million, seven hundred two thousand, seven hundred forty-nine".