1680880891 has 8 divisors (see below), whose sum is σ = 1702152144. Its totient is φ = 1659634080.

The previous prime is 1680880889. The next prime is 1680880921. The reversal of 1680880891 is 1980880861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1680880891 - 2¹ = 1680880889 is a prime.

1680880891 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1680880841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 160681 + ... + 170821.

It is an arithmetic number, because the mean of its divisors is an integer number (212769018).

Almost surely, 2^1680880891 is an apocalyptic number.

1680880891 is a deficient number, since it is larger than the sum of its proper divisors (21271253).

1680880891 is a wasteful number, since it uses less digits than its factorization.

1680880891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12221.

The product of its (nonzero) digits is 221184, while the sum is 49.

The square root of 1680880891 is about 40998.5474254881. The cubic root of 1680880891 is about 1188.9921299368.

The spelling of 1680880891 in words is "one billion, six hundred eighty million, eight hundred eighty thousand, eight hundred ninety-one".