1643340768 has 48 divisors (see below), whose sum is σ = 4567525200. Its totient is φ = 515557376.

The previous prime is 1643340749. The next prime is 1643340773. The reversal of 1643340768 is 8670433461.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent 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, 501843 + ... + 505106.

It is an arithmetic number, because the mean of its divisors is an integer number (95156775).

Almost surely, 2^1643340768 is an apocalyptic number.

It is an amenable number.

1643340768 is an abundant number, since it is smaller than the sum of its proper divisors (2924184432).

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

1643340768 is a wasteful number, since it uses less digits than its factorization.

1643340768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006979 (or 1006971 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 42.

The square root of 1643340768 is about 40538.1396711788. The cubic root of 1643340768 is about 1180.0739128268.

The spelling of 1643340768 in words is "one billion, six hundred forty-three million, three hundred forty thousand, seven hundred sixty-eight".