1965681 has 16 divisors (see below), whose sum is σ = 2976000. Its totient is φ = 1281744.

The previous prime is 1965673. The next prime is 1965701. The reversal of 1965681 is 1865691.

1965681 is a `hidden beast` number, since 1 + 96 + 568 + 1 = 666.

It is not a de Polignac number, because 1965681 - 2³ = 1965673 is a prime.

It is a super-2 number, since 2×1965681² = 7727803587522, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1965631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 495 + ... + 2043.

It is an arithmetic number, because the mean of its divisors is an integer number (186000).

2^1965681 is an apocalyptic number.

It is an amenable number.

1965681 is a deficient number, since it is larger than the sum of its proper divisors (1010319).

1965681 is a wasteful number, since it uses less digits than its factorization.

1965681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1605 (or 1599 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 1965681 is about 1402.0274605014. The cubic root of 1965681 is about 125.2672893771.

The spelling of 1965681 in words is "one million, nine hundred sixty-five thousand, six hundred eighty-one".