30040721 has 2 divisors, whose sum is σ = 30040722. Its totient is φ = 30040720.

The previous prime is 30040697. The next prime is 30040757. The reversal of 30040721 is 12704003.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19018321 + 11022400 = 4361^2 + 3320^2 .

It is a cyclic number.

It is not a de Polignac number, because 30040721 - 2⁶ = 30040657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 30040721.

It is not a weakly prime, because it can be changed into another prime (30045721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15020360 + 15020361.

It is an arithmetic number, because the mean of its divisors is an integer number (15020361).

Almost surely, 2^30040721 is an apocalyptic number.

It is an amenable number.

30040721 is a deficient number, since it is larger than the sum of its proper divisors (1).

30040721 is an equidigital number, since it uses as much as digits as its factorization.

30040721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 17.

The square root of 30040721 is about 5480.9416161824. The cubic root of 30040721 is about 310.8637754943.

Adding to 30040721 its reverse (12704003), we get a palindrome (42744724).

The spelling of 30040721 in words is "thirty million, forty thousand, seven hundred twenty-one".