640640001 has 8 divisors (see below), whose sum is σ = 854363520. Its totient is φ = 427004912.

The previous prime is 640639981. The next prime is 640640003. The reversal of 640640001 is 100046046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640640001 - 2⁵ = 640639969 is a prime.

It is a super-2 number, since 2×640640001² = 820839221762560002, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640640001.

It is not an unprimeable number, because it can be changed into a prime (640640003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2790 + ... + 35903.

It is an arithmetic number, because the mean of its divisors is an integer number (106795440).

Almost surely, 2^640640001 is an apocalyptic number.

It is an amenable number.

640640001 is a deficient number, since it is larger than the sum of its proper divisors (213723519).

640640001 is a wasteful number, since it uses less digits than its factorization.

640640001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44215.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 640640001 is about 25310.8672510446. The cubic root of 640640001 is about 862.0610387205.

Adding to 640640001 its reverse (100046046), we get a palindrome (740686047).

The spelling of 640640001 in words is "six hundred forty million, six hundred forty thousand, one".