640126 has 4 divisors (see below), whose sum is σ = 960192. Its totient is φ = 320062.

The previous prime is 640121. The next prime is 640127. The reversal of 640126 is 621046.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×640126² = 819522591752, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640121) by changing a digit.

640126 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 as a sum of consecutive naturals, namely, 160030 + ... + 160033.

It is an arithmetic number, because the mean of its divisors is an integer number (240048).

2⁶⁴⁰¹²⁶ is an apocalyptic number.

640126 is a deficient number, since it is larger than the sum of its proper divisors (320066).

640126 is a wasteful number, since it uses less digits than its factorization.

640126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320065.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 640126 is about 800.0787461244. The cubic root of 640126 is about 86.1830426212.

The spelling of 640126 in words is "six hundred forty thousand, one hundred twenty-six".