30401981 has 2 divisors, whose sum is σ = 30401982. Its totient is φ = 30401980.

The previous prime is 30401977. The next prime is 30402013. The reversal of 30401981 is 18910403.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30349081 + 52900 = 5509^2 + 230^2 .

It is a cyclic number.

It is not a de Polignac number, because 30401981 - 2² = 30401977 is a prime.

It is a super-2 number, since 2×30401981² = 1848560897448722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 30401981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30401911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15200990 + 15200991.

It is an arithmetic number, because the mean of its divisors is an integer number (15200991).

Almost surely, 2^30401981 is an apocalyptic number.

It is an amenable number.

30401981 is a deficient number, since it is larger than the sum of its proper divisors (1).

30401981 is an equidigital number, since it uses as much as digits as its factorization.

30401981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 30401981 is about 5513.7991439660. The cubic root of 30401981 is about 312.1049292316.

The spelling of 30401981 in words is "thirty million, four hundred one thousand, nine hundred eighty-one".