643707471 has 16 divisors (see below), whose sum is σ = 943044480. Its totient is φ = 387316320.

The previous prime is 643707451. The next prime is 643707487. The reversal of 643707471 is 174707346.

It is not a de Polignac number, because 643707471 - 2⁵ = 643707439 is a prime.

It is a super-3 number, since 3×643707471³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643707401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65580 + ... + 74753.

It is an arithmetic number, because the mean of its divisors is an integer number (58940280).

Almost surely, 2^643707471 is an apocalyptic number.

643707471 is a deficient number, since it is larger than the sum of its proper divisors (299337009).

643707471 is a wasteful number, since it uses less digits than its factorization.

643707471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140486.

The product of its (nonzero) digits is 98784, while the sum is 39.

The square root of 643707471 is about 25371.3907975105. The cubic root of 643707471 is about 863.4347364117.

The spelling of 643707471 in words is "six hundred forty-three million, seven hundred seven thousand, four hundred seventy-one".