1640906409 has 8 divisors (see below), whose sum is σ = 2188373152. Its totient is φ = 1093688640.

The previous prime is 1640906369. The next prime is 1640906413. The reversal of 1640906409 is 9046090461.

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

It is not a de Polignac number, because 1640906409 - 2⁸ = 1640906153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1640906459) 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 7 ways as a sum of consecutive naturals, for example, 46279 + ... + 73644.

It is an arithmetic number, because the mean of its divisors is an integer number (273546644).

Almost surely, 2^1640906409 is an apocalyptic number.

It is an amenable number.

1640906409 is a deficient number, since it is larger than the sum of its proper divisors (547466743).

1640906409 is a wasteful number, since it uses less digits than its factorization.

1640906409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124487.

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 1640906409 is about 40508.1030042139. The cubic root of 1640906409 is about 1179.4909249533.

The spelling of 1640906409 in words is "one billion, six hundred forty million, nine hundred six thousand, four hundred nine".