1008688981 has 2 divisors, whose sum is σ = 1008688982. Its totient is φ = 1008688980.

The previous prime is 1008688979. The next prime is 1008689009. The reversal of 1008688981 is 1898868001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1005207025 + 3481956 = 31705^2 + 1866^2 .

It is an emirp because it is prime and its reverse (1898868001) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1868898001 and 1008988681.

It is a cyclic number.

It is not a de Polignac number, because 1008688981 - 2¹ = 1008688979 is a prime.

It is a super-2 number, since 2×1008688981² = 2034906920781636722, which contains 22 as substring.

Together with 1008688979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1008688181) 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, 504344490 + 504344491.

It is an arithmetic number, because the mean of its divisors is an integer number (504344491).

Almost surely, 2^1008688981 is an apocalyptic number.

It is an amenable number.

1008688981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1008688981 is an equidigital number, since it uses as much as digits as its factorization.

1008688981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 221184, while the sum is 49.

The square root of 1008688981 is about 31759.8643101635. The cubic root of 1008688981 is about 1002.8879785509.

The spelling of 1008688981 in words is "one billion, eight million, six hundred eighty-eight thousand, nine hundred eighty-one".