643768560 has 100 divisors (see below), whose sum is σ = 2235926088. Its totient is φ = 171669888.

The previous prime is 643768547. The next prime is 643768561. The reversal of 643768560 is 65867346.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643768561) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 43194 + ... + 56153.

Almost surely, 2^643768560 is an apocalyptic number.

643768560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643768560 is an abundant number, since it is smaller than the sum of its proper divisors (1592157528).

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

643768560 is a wasteful number, since it uses less digits than its factorization.

643768560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99372 (or 99357 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 643768560 is about 25372.5946643224. The cubic root of 643768560 is about 863.4620493856.

The spelling of 643768560 in words is "six hundred forty-three million, seven hundred sixty-eight thousand, five hundred sixty".