1608438681 has 16 divisors (see below), whose sum is σ = 2388059520. Its totient is φ = 1069958160.

The previous prime is 1608438679. The next prime is 1608438683. The reversal of 1608438681 is 1868348061.

It is a happy number.

1608438681 is a `hidden beast` number, since 1 + 608 + 4 + 38 + 6 + 8 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1608438679) and next prime (1608438683).

It is not a de Polignac number, because 1608438681 - 2¹ = 1608438679 is a prime.

It is a super-2 number, since 2×1608438681² = 5174149981074039522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1608438683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52165 + ... + 77058.

It is an arithmetic number, because the mean of its divisors is an integer number (149253720).

Almost surely, 2^1608438681 is an apocalyptic number.

It is an amenable number.

1608438681 is a deficient number, since it is larger than the sum of its proper divisors (779620839).

1608438681 is a wasteful number, since it uses less digits than its factorization.

1608438681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129693 (or 129687 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The square root of 1608438681 is about 40105.3447934312. The cubic root of 1608438681 is about 1171.6597285982.

The spelling of 1608438681 in words is "one billion, six hundred eight million, four hundred thirty-eight thousand, six hundred eighty-one".