1640334564 has 126 divisors (see below), whose sum is σ = 4731760950. Its totient is φ = 496964160.

The previous prime is 1640334547. The next prime is 1640334613. The reversal of 1640334564 is 4654330461.

1640334564 is a `hidden beast` number, since 1 + 64 + 0 + 3 + 34 + 564 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1631513664 + 8820900 = 40392^2 + 2970^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 350512 + ... + 355160.

Almost surely, 2^1640334564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640334564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2365880475).

1640334564 is an abundant number, since it is smaller than the sum of its proper divisors (3091426386).

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

1640334564 is a wasteful number, since it uses less digits than its factorization.

1640334564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4693 (or 4665 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 1640334564 is about 40501.0439865443. The cubic root of 1640334564 is about 1179.3538941125.

The spelling of 1640334564 in words is "one billion, six hundred forty million, three hundred thirty-four thousand, five hundred sixty-four".