640402210 has 32 divisors (see below), whose sum is σ = 1318849920. Its totient is φ = 219324672.

The previous prime is 640402207. The next prime is 640402219. The reversal of 640402210 is 12204046.

It is a super-2 number, since 2×640402210² = 820229981145768200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640402219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66097 + ... + 75163.

It is an arithmetic number, because the mean of its divisors is an integer number (41214060).

Almost surely, 2^640402210 is an apocalyptic number.

640402210 is an abundant number, since it is smaller than the sum of its proper divisors (678447710).

640402210 is a wasteful number, since it uses less digits than its factorization.

640402210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10090.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 640402210 is about 25306.1694058978. The cubic root of 640402210 is about 861.9543663699.

Adding to 640402210 its reverse (12204046), we get a palindrome (652606256).

The spelling of 640402210 in words is "six hundred forty million, four hundred two thousand, two hundred ten".