643400226 has 64 divisors (see below), whose sum is σ = 1686773760. Its totient is φ = 177895440.

The previous prime is 643400213. The next prime is 643400237. The reversal of 643400226 is 622004346.

643400226 is a `hidden beast` number, since 6 + 434 + 0 + 0 + 226 = 666.

It is a super-3 number, since 3×643400226³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 643400226.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15736 + ... + 39171.

It is an arithmetic number, because the mean of its divisors is an integer number (26355840).

Almost surely, 2^643400226 is an apocalyptic number.

643400226 is an abundant number, since it is smaller than the sum of its proper divisors (1043373534).

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

643400226 is a wasteful number, since it uses less digits than its factorization.

643400226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54956 (or 54950 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 643400226 is about 25365.3351249298. The cubic root of 643400226 is about 863.2973405519.

The spelling of 643400226 in words is "six hundred forty-three million, four hundred thousand, two hundred twenty-six".