1640996805 has 32 divisors (see below), whose sum is σ = 3081786624. Its totient is φ = 729893376.

The previous prime is 1640996803. The next prime is 1640996839. The reversal of 1640996805 is 5086990461.

It is not a de Polignac number, because 1640996805 - 2¹ = 1640996803 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640996803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207312 + ... + 215081.

It is an arithmetic number, because the mean of its divisors is an integer number (96305832).

Almost surely, 2^1640996805 is an apocalyptic number.

1640996805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640996805 is a deficient number, since it is larger than the sum of its proper divisors (1440789819).

1640996805 is a wasteful number, since it uses less digits than its factorization.

1640996805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422445.

The product of its (nonzero) digits is 466560, while the sum is 48.

The square root of 1640996805 is about 40509.2187656094. The cubic root of 1640996805 is about 1179.5125835730.

The spelling of 1640996805 in words is "one billion, six hundred forty million, nine hundred ninety-six thousand, eight hundred five".