1680908121 has 24 divisors (see below), whose sum is σ = 2513726280. Its totient is φ = 1081092096.

The previous prime is 1680908111. The next prime is 1680908143. The reversal of 1680908121 is 1218090861.

It can be written as a sum of positive squares in 4 ways, for example, as 844541721 + 836366400 = 29061^2 + 28920^2 .

It is not a de Polignac number, because 1680908121 - 2⁹ = 1680907609 is a prime.

It is a super-2 number, since 2×1680908121² = 5650904222487501282, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1680908111) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 534265 + ... + 537401.

It is an arithmetic number, because the mean of its divisors is an integer number (104738595).

Almost surely, 2^1680908121 is an apocalyptic number.

It is an amenable number.

1680908121 is a deficient number, since it is larger than the sum of its proper divisors (832818159).

1680908121 is a wasteful number, since it uses less digits than its factorization.

1680908121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5225 (or 5222 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 1680908121 is about 40998.8795090793. The cubic root of 1680908121 is about 1188.9985503958.

Adding to 1680908121 its reverse (1218090861), we get a palindrome (2898998982).

The spelling of 1680908121 in words is "one billion, six hundred eighty million, nine hundred eight thousand, one hundred twenty-one".