643780047 has 8 divisors (see below), whose sum is σ = 878335744. Its totient is φ = 419205528.

The previous prime is 643780001. The next prime is 643780061. The reversal of 643780047 is 740087346.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 643780047 - 2¹¹ = 643777999 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643779987 and 643780014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643780087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2495143 + ... + 2495400.

It is an arithmetic number, because the mean of its divisors is an integer number (109791968).

Almost surely, 2^643780047 is an apocalyptic number.

643780047 is a deficient number, since it is larger than the sum of its proper divisors (234555697).

643780047 is a wasteful number, since it uses less digits than its factorization.

643780047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4990589.

The product of its (nonzero) digits is 112896, while the sum is 39.

The square root of 643780047 is about 25372.8210295978. The cubic root of 643780047 is about 863.4671850458.

The spelling of 643780047 in words is "six hundred forty-three million, seven hundred eighty thousand, forty-seven".