1640385045 has 48 divisors (see below), whose sum is σ = 3223234560. Its totient is φ = 765065088.

The previous prime is 1640384987. The next prime is 1640385049. The reversal of 1640385045 is 5405830461.

It is a happy number.

1640385045 is a `hidden beast` number, since 1 + 640 + 3 + 8 + 5 + 0 + 4 + 5 = 666.

It is not a de Polignac number, because 1640385045 - 2⁷ = 1640384917 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640385049) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 62677 + ... + 84906.

It is an arithmetic number, because the mean of its divisors is an integer number (67150720).

Almost surely, 2^1640385045 is an apocalyptic number.

1640385045 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1640385045 is a deficient number, since it is larger than the sum of its proper divisors (1582849515).

1640385045 is a wasteful number, since it uses less digits than its factorization.

1640385045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147626 (or 147623 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 1640385045 is about 40501.6671879072. The cubic root of 1640385045 is about 1179.3659921228.

The spelling of 1640385045 in words is "one billion, six hundred forty million, three hundred eighty-five thousand, forty-five".