640440033 has 8 divisors (see below), whose sum is σ = 855060096. Its totient is φ = 426390000.

The previous prime is 640440029. The next prime is 640440041. The reversal of 640440033 is 330044046.

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

It is not a de Polignac number, because 640440033 - 2² = 640440029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640439985 and 640440012.

It is not an unprimeable number, because it can be changed into a prime (640440233) 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, 139878 + ... + 144383.

It is an arithmetic number, because the mean of its divisors is an integer number (106882512).

Almost surely, 2^640440033 is an apocalyptic number.

It is an amenable number.

640440033 is a deficient number, since it is larger than the sum of its proper divisors (214620063).

640440033 is a wasteful number, since it uses less digits than its factorization.

640440033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285015.

The product of its (nonzero) digits is 3456, while the sum is 24.

The square root of 640440033 is about 25306.9167027514. The cubic root of 640440033 is about 861.9713354235.

Adding to 640440033 its reverse (330044046), we get a palindrome (970484079).

The spelling of 640440033 in words is "six hundred forty million, four hundred forty thousand, thirty-three".