640326233 has 32 divisors (see below), whose sum is σ = 738097920. Its totient is φ = 552048640.

The previous prime is 640326223. The next prime is 640326251. The reversal of 640326233 is 332623046.

It is a cyclic number.

It is not a de Polignac number, because 640326233 - 2²⁶ = 573217369 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640326196 and 640326205.

It is not an unprimeable number, because it can be changed into a prime (640326223) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 945491 + ... + 946167.

It is an arithmetic number, because the mean of its divisors is an integer number (23065560).

Almost surely, 2^640326233 is an apocalyptic number.

It is an amenable number.

640326233 is a deficient number, since it is larger than the sum of its proper divisors (97771687).

640326233 is a wasteful number, since it uses less digits than its factorization.

640326233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817.

The product of its (nonzero) digits is 15552, while the sum is 29.

The square root of 640326233 is about 25304.6682056888. The cubic root of 640326233 is about 861.9202777426.

Adding to 640326233 its reverse (332623046), we get a palindrome (972949279).

The spelling of 640326233 in words is "six hundred forty million, three hundred twenty-six thousand, two hundred thirty-three".