721849 has 2 divisors, whose sum is σ = 721850. Its totient is φ = 721848.

The previous prime is 721843. The next prime is 721859. The reversal of 721849 is 948127.

721849 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 446224 + 275625 = 668^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 721849 - 2⁹ = 721337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 721849.

It is not a weakly prime, because it can be changed into another prime (721843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360924 + 360925.

It is an arithmetic number, because the mean of its divisors is an integer number (360925).

2⁷²¹⁸⁴⁹ is an apocalyptic number.

It is an amenable number.

721849 is a deficient number, since it is larger than the sum of its proper divisors (1).

721849 is an equidigital number, since it uses as much as digits as its factorization.

721849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 31.

The square root of 721849 is about 849.6169725235. The cubic root of 721849 is about 89.7047526572.

The spelling of 721849 in words is "seven hundred twenty-one thousand, eight hundred forty-nine".