1680920447 has 4 divisors (see below), whose sum is σ = 1681067256. Its totient is φ = 1680773640.

The previous prime is 1680920413. The next prime is 1680920473. The reversal of 1680920447 is 7440290861.

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 1680920447 - 2⁸ = 1680920191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680920497) 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, 54629 + ... + 79662.

It is an arithmetic number, because the mean of its divisors is an integer number (420266814).

Almost surely, 2^1680920447 is an apocalyptic number.

1680920447 is a deficient number, since it is larger than the sum of its proper divisors (146809).

1680920447 is a wasteful number, since it uses less digits than its factorization.

1680920447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146808.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 1680920447 is about 40999.0298299850. The cubic root of 1680920447 is about 1189.0014566741.

The spelling of 1680920447 in words is "one billion, six hundred eighty million, nine hundred twenty thousand, four hundred forty-seven".