640011 has 4 divisors (see below), whose sum is σ = 853352. Its totient is φ = 426672.

The previous prime is 640009. The next prime is 640019. The reversal of 640011 is 110046.

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

It is not a de Polignac number, because 640011 - 2¹ = 640009 is a prime.

It is a super-2 number, since 2×640011² = 819228160242, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640011.

It is not an unprimeable number, because it can be changed into a prime (640019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106666 + ... + 106671.

It is an arithmetic number, because the mean of its divisors is an integer number (213338).

2⁶⁴⁰⁰¹¹ is an apocalyptic number.

640011 is a deficient number, since it is larger than the sum of its proper divisors (213341).

640011 is a wasteful number, since it uses less digits than its factorization.

640011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213340.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 640011 is about 800.0068749705. The cubic root of 640011 is about 86.1778813231.

Adding to 640011 its reverse (110046), we get a palindrome (750057).

The spelling of 640011 in words is "six hundred forty thousand, eleven".