30281021 has 2 divisors, whose sum is σ = 30281022. Its totient is φ = 30281020.

The previous prime is 30280997. The next prime is 30281023. The reversal of 30281021 is 12018203.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19456921 + 10824100 = 4411^2 + 3290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30281021 is a prime.

Together with 30281023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30281023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15140510 + 15140511.

It is an arithmetic number, because the mean of its divisors is an integer number (15140511).

Almost surely, 2^30281021 is an apocalyptic number.

It is an amenable number.

30281021 is a deficient number, since it is larger than the sum of its proper divisors (1).

30281021 is an equidigital number, since it uses as much as digits as its factorization.

30281021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 30281021 is about 5502.8193682875. The cubic root of 30281021 is about 311.6904563359.

Adding to 30281021 its reverse (12018203), we get a palindrome (42299224).

The spelling of 30281021 in words is "thirty million, two hundred eighty-one thousand, twenty-one".