915005981 has 2 divisors, whose sum is σ = 915005982. Its totient is φ = 915005980.

The previous prime is 915005963. The next prime is 915005983. The reversal of 915005981 is 189500519.

915005981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 667447225 + 247558756 = 25835^2 + 15734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-915005981 is a prime.

It is a super-2 number, since 2×915005981² = 1674471890531544722, which contains 22 as substring.

Together with 915005983, 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 (915005983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 457502990 + 457502991.

It is an arithmetic number, because the mean of its divisors is an integer number (457502991).

Almost surely, 2^915005981 is an apocalyptic number.

It is an amenable number.

915005981 is a deficient number, since it is larger than the sum of its proper divisors (1).

915005981 is an equidigital number, since it uses as much as digits as its factorization.

915005981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16200, while the sum is 38.

The square root of 915005981 is about 30249.0657872272. The cubic root of 915005981 is about 970.8258036481.

The spelling of 915005981 in words is "nine hundred fifteen million, five thousand, nine hundred eighty-one".