989525981 has 2 divisors, whose sum is σ = 989525982. Its totient is φ = 989525980.

The previous prime is 989525951. The next prime is 989525989. The reversal of 989525981 is 189525989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 522533881 + 466992100 = 22859^2 + 21610^2 .

It is a cyclic number.

It is not a de Polignac number, because 989525981 - 2¹⁴ = 989509597 is a prime.

It is a super-2 number, since 2×989525981² = 1958323334148024722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (989525989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 494762990 + 494762991.

It is an arithmetic number, because the mean of its divisors is an integer number (494762991).

Almost surely, 2^989525981 is an apocalyptic number.

It is an amenable number.

989525981 is a deficient number, since it is larger than the sum of its proper divisors (1).

989525981 is an equidigital number, since it uses as much as digits as its factorization.

989525981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2332800, while the sum is 56.

The square root of 989525981 is about 31456.7318868315. The cubic root of 989525981 is about 996.4963994524.

The spelling of 989525981 in words is "nine hundred eighty-nine million, five hundred twenty-five thousand, nine hundred eighty-one".