643042726 has 16 divisors (see below), whose sum is σ = 1038945600. Its totient is φ = 297514728.

The previous prime is 643042691. The next prime is 643042733. The reversal of 643042726 is 627240346.

It is a super-2 number, since 2×643042726² = 827007894923022152, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643042691 and 643042700.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195136 + ... + 198403.

It is an arithmetic number, because the mean of its divisors is an integer number (64934100).

Almost surely, 2^643042726 is an apocalyptic number.

643042726 is a deficient number, since it is larger than the sum of its proper divisors (395902874).

643042726 is a wasteful number, since it uses less digits than its factorization.

643042726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393603.

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 643042726 is about 25358.2871266969. The cubic root of 643042726 is about 863.1374162587.

The spelling of 643042726 in words is "six hundred forty-three million, forty-two thousand, seven hundred twenty-six".