30023721 has 36 divisors (see below), whose sum is σ = 54339012. Its totient is φ = 15833664.

The previous prime is 30023711. The next prime is 30023797. The reversal of 30023721 is 12732003.

It can be written as a sum of positive squares in 2 ways, for example, as 15093225 + 14930496 = 3885^2 + 3864^2 .

It is not a de Polignac number, because 30023721 - 2⁶ = 30023657 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 30023694 and 30023703.

It is not an unprimeable number, because it can be changed into a prime (30023711) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3115 + ... + 8351.

It is an arithmetic number, because the mean of its divisors is an integer number (1509417).

Almost surely, 2^30023721 is an apocalyptic number.

It is an amenable number.

30023721 is a deficient number, since it is larger than the sum of its proper divisors (24315291).

30023721 is a wasteful number, since it uses less digits than its factorization.

30023721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5270 (or 5260 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 30023721 is about 5479.3905683023. The cubic root of 30023721 is about 310.8051253111.

Adding to 30023721 its reverse (12732003), we get a palindrome (42755724).

The spelling of 30023721 in words is "thirty million, twenty-three thousand, seven hundred twenty-one".