643378680 has 128 divisors (see below), whose sum is σ = 2450995200. Its totient is φ = 147056256.

The previous prime is 643378669. The next prime is 643378691. The reversal of 643378680 is 86873346.

It is an interprime number because it is at equal distance from previous prime (643378669) and next prime (643378691).

It is a super-2 number, since 2×643378680² = 827872251757084800, which contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 34992 + ... + 50111.

It is an arithmetic number, because the mean of its divisors is an integer number (19148400).

Almost surely, 2^643378680 is an apocalyptic number.

643378680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

643378680 is an abundant number, since it is smaller than the sum of its proper divisors (1807616520).

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

643378680 is a wasteful number, since it uses less digits than its factorization.

643378680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85130 (or 85120 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The square root of 643378680 is about 25364.9104078844. The cubic root of 643378680 is about 863.2877038275.

The spelling of 643378680 in words is "six hundred forty-three million, three hundred seventy-eight thousand, six hundred eighty".