1681629665 has 8 divisors (see below), whose sum is σ = 2023773120. Its totient is φ = 1341425392.

The previous prime is 1681629617. The next prime is 1681629673. The reversal of 1681629665 is 5669261861.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1681629665 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 482885 + ... + 486354.

It is an arithmetic number, because the mean of its divisors is an integer number (252971640).

Almost surely, 2^1681629665 is an apocalyptic number.

It is an amenable number.

1681629665 is a deficient number, since it is larger than the sum of its proper divisors (342143455).

1681629665 is an equidigital number, since it uses as much as digits as its factorization.

1681629665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969591.

The product of its digits is 933120, while the sum is 50.

The square root of 1681629665 is about 41007.6781225175. The cubic root of 1681629665 is about 1189.1686552800.

The spelling of 1681629665 in words is "one billion, six hundred eighty-one million, six hundred twenty-nine thousand, six hundred sixty-five".