30720691 has 2 divisors, whose sum is σ = 30720692. Its totient is φ = 30720690.

The previous prime is 30720689. The next prime is 30720719. The reversal of 30720691 is 19602703.

It is an a-pointer prime, because the next prime (30720719) can be obtained adding 30720691 to its sum of digits (28).

It is a weak prime.

It is an emirp because it is prime and its reverse (19602703) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30720691 - 2¹ = 30720689 is a prime.

Together with 30720689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (30720601) 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 as a sum of consecutive naturals, namely, 15360345 + 15360346.

It is an arithmetic number, because the mean of its divisors is an integer number (15360346).

Almost surely, 2^30720691 is an apocalyptic number.

30720691 is a deficient number, since it is larger than the sum of its proper divisors (1).

30720691 is an equidigital number, since it uses as much as digits as its factorization.

30720691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 30720691 is about 5542.6249196568. The cubic root of 30720691 is about 313.1917595168.

The spelling of 30720691 in words is "thirty million, seven hundred twenty thousand, six hundred ninety-one".