440721217 has 2 divisors, whose sum is σ = 440721218. Its totient is φ = 440721216.

The previous prime is 440721199. The next prime is 440721223. The reversal of 440721217 is 712127044.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 363703041 + 77018176 = 19071^2 + 8776^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-440721217 is a prime.

It is a super-2 number, since 2×440721217² = 388470382227922178, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (440721247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 220360608 + 220360609.

It is an arithmetic number, because the mean of its divisors is an integer number (220360609).

Almost surely, 2^440721217 is an apocalyptic number.

It is an amenable number.

440721217 is a deficient number, since it is larger than the sum of its proper divisors (1).

440721217 is an equidigital number, since it uses as much as digits as its factorization.

440721217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3136, while the sum is 28.

The square root of 440721217 is about 20993.3612601698. The cubic root of 440721217 is about 761.0058340844.

The spelling of 440721217 in words is "four hundred forty million, seven hundred twenty-one thousand, two hundred seventeen".