1530721 has 2 divisors, whose sum is σ = 1530722. Its totient is φ = 1530720.

The previous prime is 1530713. The next prime is 1530779. The reversal of 1530721 is 1270351.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1527696 + 3025 = 1236^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 1530721 - 2³ = 1530713 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1530791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765360 + 765361.

It is an arithmetic number, because the mean of its divisors is an integer number (765361).

2^1530721 is an apocalyptic number.

It is an amenable number.

1530721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1530721 is an equidigital number, since it uses as much as digits as its factorization.

1530721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 19.

The square root of 1530721 is about 1237.2231003340. The cubic root of 1530721 is about 115.2476327343.

The spelling of 1530721 in words is "one million, five hundred thirty thousand, seven hundred twenty-one".