1688081 has 2 divisors, whose sum is σ = 1688082. Its totient is φ = 1688080.

The previous prime is 1688077. The next prime is 1688101. The reversal of 1688081 is 1808861.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1401856 + 286225 = 1184^2 + 535^2 .

It is a cyclic number.

It is not a de Polignac number, because 1688081 - 2² = 1688077 is a prime.

It is a super-2 number, since 2×1688081² = 5699234925122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1688041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844040 + 844041.

It is an arithmetic number, because the mean of its divisors is an integer number (844041).

2^1688081 is an apocalyptic number.

It is an amenable number.

1688081 is a deficient number, since it is larger than the sum of its proper divisors (1).

1688081 is an equidigital number, since it uses as much as digits as its factorization.

1688081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3072, while the sum is 32.

The square root of 1688081 is about 1299.2617134357. The cubic root of 1688081 is about 119.0687407374.

It can be divided in two parts, 16880 and 81, that added together give a palindrome (16961).

The spelling of 1688081 in words is "one million, six hundred eighty-eight thousand, eighty-one".