959999981 has 2 divisors, whose sum is σ = 959999982. Its totient is φ = 959999980.

The previous prime is 959999969. The next prime is 959999987. The reversal of 959999981 is 189999959.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 941937481 + 18062500 = 30691^2 + 4250^2 .

It is a cyclic number.

It is not a de Polignac number, because 959999981 - 2¹⁴ = 959983597 is a prime.

It is a super-2 number, since 2×959999981² = 1843199927040000722, 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 (959999987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 479999990 + 479999991.

It is an arithmetic number, because the mean of its divisors is an integer number (479999991).

Almost surely, 2^959999981 is an apocalyptic number.

It is an amenable number.

959999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

959999981 is an equidigital number, since it uses as much as digits as its factorization.

959999981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21257640, while the sum is 68.

The square root of 959999981 is about 30983.8664630482. The cubic root of 959999981 is about 986.4848232241.

The spelling of 959999981 in words is "nine hundred fifty-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".