1608731881 has 9 divisors (see below), whose sum is σ = 1698662973. Its totient is φ = 1523339820.

The previous prime is 1608731863. The next prime is 1608731897. The reversal of 1608731881 is 1881378061.

The square root of 1608731881 is 40109.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1608731881 - 2⁷ = 1608731753 is a prime.

It is a super-2 number, since 2×1608731881² = 5176036529891596322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1608731821) 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 8 ways as a sum of consecutive naturals, for example, 761016 + ... + 763126.

Almost surely, 2^1608731881 is an apocalyptic number.

1608731881 is the 40109-th square number.

1608731881 is the 20055-th centered octagonal number.

It is an amenable number.

1608731881 is a deficient number, since it is larger than the sum of its proper divisors (89931092).

1608731881 is an frugal number, since it uses more digits than its factorization.

1608731881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4260 (or 2130 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 43.

The cubic root of 1608731881 is about 1171.7309176680.

The spelling of 1608731881 in words is "one billion, six hundred eight million, seven hundred thirty-one thousand, eight hundred eighty-one".