1608881685889 has 9 divisors (see below), whose sum is σ = 1649133106761. Its totient is φ = 1569589932480.

The previous prime is 1608881685863. The next prime is 1608881685937. The reversal of 1608881685889 is 9885861888061.

The square root of 1608881685889 is 1268417.

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

It can be written as a sum of positive squares in 4 ways, for example, as 1142130377025 + 466751308864 = 1068705^2 + 683192^2 .

It is not a de Polignac number, because 1608881685889 - 2⁹ = 1608881685377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1608881685689) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 51989629 + ... + 52020565.

Almost surely, 2^{1608881685889} is an apocalyptic number.

1608881685889 is the 1268417-th square number.

1608881685889 is the 634209-th centered octagonal number.

It is an amenable number.

1608881685889 is a deficient number, since it is larger than the sum of its proper divisors (40251420872).

1608881685889 is an frugal number, since it uses more digits than its factorization.

1608881685889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61956 (or 30978 counting only the distinct ones).

The product of its (nonzero) digits is 424673280, while the sum is 76.

The spelling of 1608881685889 in words is "one trillion, six hundred eight billion, eight hundred eighty-one million, six hundred eighty-five thousand, eight hundred eighty-nine".