643880790 has 48 divisors (see below), whose sum is σ = 1913247648. Its totient is φ = 147172608.

The previous prime is 643880789. The next prime is 643880801. The reversal of 643880790 is 97088346.

It is a happy number.

643880790 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 510387 + ... + 511646.

It is an arithmetic number, because the mean of its divisors is an integer number (39859326).

Almost surely, 2^643880790 is an apocalyptic number.

643880790 is an abundant number, since it is smaller than the sum of its proper divisors (1269366858).

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

643880790 is a wasteful number, since it uses less digits than its factorization.

643880790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1022053 (or 1022050 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 643880790 is about 25374.8062061565. The cubic root of 643880790 is about 863.5122230666.

The spelling of 643880790 in words is "six hundred forty-three million, eight hundred eighty thousand, seven hundred ninety".