1640816081 has 16 divisors (see below), whose sum is σ = 1795415040. Its totient is φ = 1492784640.

The previous prime is 1640816077. The next prime is 1640816087. The reversal of 1640816081 is 1806180461.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1640816081 - 2² = 1640816077 is a prime.

It is a super-2 number, since 2×1640816081² = 5384554823336397122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640816087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 872300 + ... + 874178.

It is an arithmetic number, because the mean of its divisors is an integer number (112213440).

Almost surely, 2^1640816081 is an apocalyptic number.

It is an amenable number.

1640816081 is a deficient number, since it is larger than the sum of its proper divisors (154598959).

1640816081 is a wasteful number, since it uses less digits than its factorization.

1640816081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3584.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 1640816081 is about 40506.9880514461. The cubic root of 1640816081 is about 1179.4692818316.

The spelling of 1640816081 in words is "one billion, six hundred forty million, eight hundred sixteen thousand, eighty-one".