721481 has 2 divisors, whose sum is σ = 721482. Its totient is φ = 721480.

The previous prime is 721451. The next prime is 721499. The reversal of 721481 is 184127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 462400 + 259081 = 680^2 + 509^2 .

It is a cyclic number.

It is not a de Polignac number, because 721481 - 2¹⁴ = 705097 is a prime.

It is a super-2 number, since 2×721481² = 1041069666722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (721451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360740 + 360741.

It is an arithmetic number, because the mean of its divisors is an integer number (360741).

2⁷²¹⁴⁸¹ is an apocalyptic number.

It is an amenable number.

721481 is a deficient number, since it is larger than the sum of its proper divisors (1).

721481 is an equidigital number, since it uses as much as digits as its factorization.

721481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 23.

The square root of 721481 is about 849.4003767364. The cubic root of 721481 is about 89.6895061812.

The spelling of 721481 in words is "seven hundred twenty-one thousand, four hundred eighty-one".