30523981 has 2 divisors, whose sum is σ = 30523982. Its totient is φ = 30523980.

The previous prime is 30523949. The next prime is 30524041. The reversal of 30523981 is 18932503.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27405225 + 3118756 = 5235^2 + 1766^2 .

It is an emirp because it is prime and its reverse (18932503) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30523981 - 2⁵ = 30523949 is a prime.

It is a super-2 number, since 2×30523981² = 1863426832176722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30523931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15261990 + 15261991.

It is an arithmetic number, because the mean of its divisors is an integer number (15261991).

Almost surely, 2^30523981 is an apocalyptic number.

It is an amenable number.

30523981 is a deficient number, since it is larger than the sum of its proper divisors (1).

30523981 is an equidigital number, since it uses as much as digits as its factorization.

30523981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 30523981 is about 5524.8512197162. The cubic root of 30523981 is about 312.5218536184.

The spelling of 30523981 in words is "thirty million, five hundred twenty-three thousand, nine hundred eighty-one".