1640555065 has 8 divisors (see below), whose sum is σ = 1980744768. Its totient is φ = 1304391600.

The previous prime is 1640555047. The next prime is 1640555071. The reversal of 1640555065 is 5605550461.

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

It is a de Polignac number, because none of the positive numbers 2^k-1640555065 is a prime.

It is a Duffinian number.

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, 1005661 + ... + 1007290.

It is an arithmetic number, because the mean of its divisors is an integer number (247593096).

Almost surely, 2^1640555065 is an apocalyptic number.

It is an amenable number.

1640555065 is a deficient number, since it is larger than the sum of its proper divisors (340189703).

1640555065 is a wasteful number, since it uses less digits than its factorization.

1640555065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2013119.

The product of its (nonzero) digits is 90000, while the sum is 37.

The square root of 1640555065 is about 40503.7660594666. The cubic root of 1640555065 is about 1179.4067363938.

The spelling of 1640555065 in words is "one billion, six hundred forty million, five hundred fifty-five thousand, sixty-five".