30970781 has 2 divisors, whose sum is σ = 30970782. Its totient is φ = 30970780.

The previous prime is 30970757. The next prime is 30970783. The reversal of 30970781 is 18707903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23863225 + 7107556 = 4885^2 + 2666^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30970781 is a prime.

It is a super-2 number, since 2×30970781² = 1918378551499922, which contains 22 as substring.

Together with 30970783, 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 (30970783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15485390 + 15485391.

It is an arithmetic number, because the mean of its divisors is an integer number (15485391).

Almost surely, 2^30970781 is an apocalyptic number.

It is an amenable number.

30970781 is a deficient number, since it is larger than the sum of its proper divisors (1).

30970781 is an equidigital number, since it uses as much as digits as its factorization.

30970781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 30970781 is about 5565.1398005800. The cubic root of 30970781 is about 314.0393374385.

The spelling of 30970781 in words is "thirty million, nine hundred seventy thousand, seven hundred eighty-one".