640123312 has 10 divisors (see below), whose sum is σ = 1240238948. Its totient is φ = 320061648.

The previous prime is 640123301. The next prime is 640123313. The reversal of 640123312 is 213321046.

It is not an unprimeable number, because it can be changed into a prime (640123313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20003838 + ... + 20003869.

Almost surely, 2^640123312 is an apocalyptic number.

It is an amenable number.

640123312 is a deficient number, since it is larger than the sum of its proper divisors (600115636).

640123312 is a wasteful number, since it uses less digits than its factorization.

640123312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40007715 (or 40007709 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 640123312 is about 25300.6583313557. The cubic root of 640123312 is about 861.8292198856.

Adding to 640123312 its reverse (213321046), we get a palindrome (853444358).

The spelling of 640123312 in words is "six hundred forty million, one hundred twenty-three thousand, three hundred twelve".