1640865006 has 64 divisors (see below), whose sum is σ = 3983420160. Its totient is φ = 496536480.

The previous prime is 1640864983. The next prime is 1640865053. The reversal of 1640865006 is 6005680461.

1640865006 is a `hidden beast` number, since 1 + 640 + 8 + 6 + 5 + 0 + 0 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 561060 + ... + 563976.

It is an arithmetic number, because the mean of its divisors is an integer number (62240940).

Almost surely, 2^1640865006 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640865006, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1991710080).

1640865006 is an abundant number, since it is smaller than the sum of its proper divisors (2342555154).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1640865006 is a wasteful number, since it uses less digits than its factorization.

1640865006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886 (or 3880 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 1640865006 is about 40507.5919550891. The cubic root of 1640865006 is about 1179.4810046488.

The spelling of 1640865006 in words is "one billion, six hundred forty million, eight hundred sixty-five thousand, six".