438721 has 2 divisors, whose sum is σ = 438722. Its totient is φ = 438720.

The previous prime is 438707. The next prime is 438733. The reversal of 438721 is 127834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 404496 + 34225 = 636^2 + 185^2 .

It is a cyclic number.

It is not a de Polignac number, because 438721 - 2¹¹ = 436673 is a prime.

It is a super-2 number, since 2×438721² = 384952231682, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is equal to p₃₆₈₄₄ and since 438721 and 36844 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (438701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 219360 + 219361.

It is an arithmetic number, because the mean of its divisors is an integer number (219361).

2⁴³⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

438721 is a deficient number, since it is larger than the sum of its proper divisors (1).

438721 is an equidigital number, since it uses as much as digits as its factorization.

438721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 25.

The square root of 438721 is about 662.3601739235. The cubic root of 438721 is about 75.9852810831.

The spelling of 438721 in words is "four hundred thirty-eight thousand, seven hundred twenty-one".