30020561 has 2 divisors, whose sum is σ = 30020562. Its totient is φ = 30020560.
The previous prime is 30020527. The next prime is 30020563. The reversal of 30020561 is 16502003.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 27888961 + 2131600 = 5281^2 + 1460^2 .
It is a cyclic number.
It is not a de Polignac number, because 30020561 - 210 = 30019537 is a prime.
It is a Sophie Germain prime.
Together with 30020563, it forms a pair of twin primes.
It is a Chen prime.
It is a Curzon number.
It is not a weakly prime, because it can be changed into another prime (30020563) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15010280 + 15010281.
It is an arithmetic number, because the mean of its divisors is an integer number (15010281).
Almost surely, 230020561 is an apocalyptic number.
It is an amenable number.
30020561 is a deficient number, since it is larger than the sum of its proper divisors (1).
30020561 is an equidigital number, since it uses as much as digits as its factorization.
30020561 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 180, while the sum is 17.
The square root of 30020561 is about 5479.1022074789. The cubic root of 30020561 is about 310.7942208371.
Adding to 30020561 its reverse (16502003), we get a palindrome (46522564).
The spelling of 30020561 in words is "thirty million, twenty thousand, five hundred sixty-one".
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