30206921 has 2 divisors, whose sum is σ = 30206922. Its totient is φ = 30206920.

The previous prime is 30206899. The next prime is 30206923. The reversal of 30206921 is 12960203.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29822521 + 384400 = 5461^2 + 620^2 .

It is a cyclic number.

It is not a de Polignac number, because 30206921 - 2⁶ = 30206857 is a prime.

Together with 30206923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (30206923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15103460 + 15103461.

It is an arithmetic number, because the mean of its divisors is an integer number (15103461).

Almost surely, 2^30206921 is an apocalyptic number.

It is an amenable number.

30206921 is a deficient number, since it is larger than the sum of its proper divisors (1).

30206921 is an equidigital number, since it uses as much as digits as its factorization.

30206921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 30206921 is about 5496.0823319889. The cubic root of 30206921 is about 311.4360051191.

The spelling of 30206921 in words is "thirty million, two hundred six thousand, nine hundred twenty-one".