30720071 has 4 divisors (see below), whose sum is σ = 32527152. Its totient is φ = 28912992.

The previous prime is 30720049. The next prime is 30720073. The reversal of 30720071 is 17002703.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17002703 = 17 ⋅1000159.

It is a cyclic number.

It is not a de Polignac number, because 30720071 - 2⁶ = 30720007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30720073) 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 in 3 ways as a sum of consecutive naturals, for example, 903515 + ... + 903548.

It is an arithmetic number, because the mean of its divisors is an integer number (8131788).

Almost surely, 2^30720071 is an apocalyptic number.

30720071 is a deficient number, since it is larger than the sum of its proper divisors (1807081).

30720071 is a wasteful number, since it uses less digits than its factorization.

30720071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1807080.

The product of its (nonzero) digits is 294, while the sum is 20.

The square root of 30720071 is about 5542.5689891963. The cubic root of 30720071 is about 313.1896525742.

Adding to 30720071 its reverse (17002703), we get a palindrome (47722774).

The spelling of 30720071 in words is "thirty million, seven hundred twenty thousand, seventy-one".