1680918971 has 4 divisors (see below), whose sum is σ = 1689366000. Its totient is φ = 1672471944.

The previous prime is 1680918949. The next prime is 1680918997. The reversal of 1680918971 is 1798190861.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1680918971 - 2⁶ = 1680918907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1680918901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4223216 + ... + 4223613.

It is an arithmetic number, because the mean of its divisors is an integer number (422341500).

Almost surely, 2^1680918971 is an apocalyptic number.

1680918971 is a deficient number, since it is larger than the sum of its proper divisors (8447029).

1680918971 is an equidigital number, since it uses as much as digits as its factorization.

1680918971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8447028.

The product of its (nonzero) digits is 217728, while the sum is 50.

The square root of 1680918971 is about 40999.0118295551. The cubic root of 1680918971 is about 1189.0011086571.

The spelling of 1680918971 in words is "one billion, six hundred eighty million, nine hundred eighteen thousand, nine hundred seventy-one".