1608886981 has 8 divisors (see below), whose sum is σ = 1736889560. Its totient is φ = 1481490432.

The previous prime is 1608886973. The next prime is 1608887003. The reversal of 1608886981 is 1896888061.

It can be written as a sum of positive squares in 4 ways, for example, as 625500100 + 983386881 = 25010^2 + 31359^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1608886981 - 2³ = 1608886973 is a prime.

It is a super-2 number, since 2×1608886981² = 5177034635262588722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1608886381) 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 in 7 ways as a sum of consecutive naturals, for example, 145980 + ... + 156613.

It is an arithmetic number, because the mean of its divisors is an integer number (217111195).

Almost surely, 2^1608886981 is an apocalyptic number.

It is an amenable number.

1608886981 is a deficient number, since it is larger than the sum of its proper divisors (128002579).

1608886981 is a wasteful number, since it uses less digits than its factorization.

1608886981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303015.

The product of its (nonzero) digits is 1327104, while the sum is 55.

The square root of 1608886981 is about 40110.9334346634. The cubic root of 1608886981 is about 1171.7685725081.

The spelling of 1608886981 in words is "one billion, six hundred eight million, eight hundred eighty-six thousand, nine hundred eighty-one".