30902981 has 2 divisors, whose sum is σ = 30902982. Its totient is φ = 30902980.

The previous prime is 30902969. The next prime is 30903043. The reversal of 30902981 is 18920903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29920900 + 982081 = 5470^2 + 991^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30902981 is a prime.

It is a super-2 number, since 2×30902981² = 1909988469372722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30902941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15451490 + 15451491.

It is an arithmetic number, because the mean of its divisors is an integer number (15451491).

Almost surely, 2^30902981 is an apocalyptic number.

It is an amenable number.

30902981 is a deficient number, since it is larger than the sum of its proper divisors (1).

30902981 is an equidigital number, since it uses as much as digits as its factorization.

30902981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 30902981 is about 5559.0449719354. The cubic root of 30902981 is about 313.8100092091.

The spelling of 30902981 in words is "thirty million, nine hundred two thousand, nine hundred eighty-one".