643288680 has 48 divisors (see below), whose sum is σ = 2090689380. Its totient is φ = 171543552.

The previous prime is 643288669. The next prime is 643288699. The reversal of 643288680 is 86882346.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 640798596 + 2490084 = 25314^2 + 1578^2 .

It is a super-2 number, since 2×643288680² = 827640651632284800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 893097 + ... + 893816.

Almost surely, 2^643288680 is an apocalyptic number.

643288680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643288680 is an abundant number, since it is smaller than the sum of its proper divisors (1447400700).

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

643288680 is a wasteful number, since it uses less digits than its factorization.

643288680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1786930 (or 1786923 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 643288680 is about 25363.1362414036. The cubic root of 643288680 is about 863.2474478481.

The spelling of 643288680 in words is "six hundred forty-three million, two hundred eighty-eight thousand, six hundred eighty".