736721 has 2 divisors, whose sum is σ = 736722. Its totient is φ = 736720.

The previous prime is 736717. The next prime is 736741. The reversal of 736721 is 127637.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640000 + 96721 = 800^2 + 311^2 .

It is an emirp because it is prime and its reverse (127637) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 736721 - 2² = 736717 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (736741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 368360 + 368361.

It is an arithmetic number, because the mean of its divisors is an integer number (368361).

2⁷³⁶⁷²¹ is an apocalyptic number.

It is an amenable number.

736721 is a deficient number, since it is larger than the sum of its proper divisors (1).

736721 is an equidigital number, since it uses as much as digits as its factorization.

736721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1764, while the sum is 26.

The square root of 736721 is about 858.3245306992. The cubic root of 736721 is about 90.3166214400.

The spelling of 736721 in words is "seven hundred thirty-six thousand, seven hundred twenty-one".