30720125 has 16 divisors (see below), whose sum is σ = 39070512. Its totient is φ = 24107200.

The previous prime is 30720119. The next prime is 30720127. The reversal of 30720125 is 52102703.

It can be written as a sum of positive squares in 8 ways, for example, as 10407076 + 20313049 = 3226^2 + 4507^2 .

It is not a de Polignac number, because 30720125 - 2¹² = 30716029 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 30720097 and 30720106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30720127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4307 + ... + 8943.

It is an arithmetic number, because the mean of its divisors is an integer number (2441907).

Almost surely, 2^30720125 is an apocalyptic number.

It is an amenable number.

30720125 is a deficient number, since it is larger than the sum of its proper divisors (8350387).

30720125 is an equidigital number, since it uses as much as digits as its factorization.

30720125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4705 (or 4695 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 30720125 is about 5542.5738605814. The cubic root of 30720125 is about 313.1898360833.

Adding to 30720125 its reverse (52102703), we get a palindrome (82822828).

The spelling of 30720125 in words is "thirty million, seven hundred twenty thousand, one hundred twenty-five".