643501534 has 32 divisors (see below), whose sum is σ = 1095929856. Its totient is φ = 281288160.

The previous prime is 643501513. The next prime is 643501541. The reversal of 643501534 is 435105346.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a junction number, because it is equal to n+sod(n) for n = 643501496 and 643501505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29389 + ... + 46375.

It is an arithmetic number, because the mean of its divisors is an integer number (34247808).

Almost surely, 2^643501534 is an apocalyptic number.

643501534 is a deficient number, since it is larger than the sum of its proper divisors (452428322).

643501534 is a wasteful number, since it uses less digits than its factorization.

643501534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17080.

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 643501534 is about 25367.3320236875. The cubic root of 643501534 is about 863.3426489688.

The spelling of 643501534 in words is "six hundred forty-three million, five hundred one thousand, five hundred thirty-four".