30999281 has 2 divisors, whose sum is σ = 30999282. Its totient is φ = 30999280.

The previous prime is 30999277. The next prime is 30999299. The reversal of 30999281 is 18299903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19439281 + 11560000 = 4409^2 + 3400^2 .

It is an emirp because it is prime and its reverse (18299903) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30999281 - 2² = 30999277 is a prime.

It is a super-2 number, since 2×30999281² = 1921910845033922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (30999271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15499640 + 15499641.

It is an arithmetic number, because the mean of its divisors is an integer number (15499641).

Almost surely, 2^30999281 is an apocalyptic number.

It is an amenable number.

30999281 is a deficient number, since it is larger than the sum of its proper divisors (1).

30999281 is an equidigital number, since it uses as much as digits as its factorization.

30999281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 30999281 is about 5567.6997943495. The cubic root of 30999281 is about 314.1356365616.

The spelling of 30999281 in words is "thirty million, nine hundred ninety-nine thousand, two hundred eighty-one".