1681946687 has 8 divisors (see below), whose sum is σ = 1688908032. Its totient is φ = 1674999000.

The previous prime is 1681946683. The next prime is 1681946701. The reversal of 1681946687 is 7866491861.

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 1681946687 - 2² = 1681946683 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 (1681946683) 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, 294812 + ... + 300462.

It is an arithmetic number, because the mean of its divisors is an integer number (211113504).

Almost surely, 2^1681946687 is an apocalyptic number.

1681946687 is a deficient number, since it is larger than the sum of its proper divisors (6961345).

1681946687 is an equidigital number, since it uses as much as digits as its factorization.

1681946687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6829.

The product of its digits is 3483648, while the sum is 56.

The square root of 1681946687 is about 41011.5433384309. The cubic root of 1681946687 is about 1189.2433782200.

The spelling of 1681946687 in words is "one billion, six hundred eighty-one million, nine hundred forty-six thousand, six hundred eighty-seven".