6431276640 has 192 divisors, whose sum is σ = 21247531200. Its totient is φ = 1632927744.

The previous prime is 6431276609. The next prime is 6431276653. The reversal of 6431276640 is 466721346.

It is a happy number.

It is a super-2 number, since 2×6431276640² = 82722638440419379200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1012996 + ... + 1019324.

It is an arithmetic number, because the mean of its divisors is an integer number (110664225).

Almost surely, 2^6431276640 is an apocalyptic number.

6431276640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6431276640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10623765600).

6431276640 is an abundant number, since it is smaller than the sum of its proper divisors (14816254560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6431276640 is a wasteful number, since it uses less digits than its factorization.

6431276640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6449 (or 6441 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 39.

The square root of 6431276640 is about 80195.2407565437. The cubic root of 6431276640 is about 1859.6550637961.

Adding to 6431276640 its reverse (466721346), we get a palindrome (6897997986).

The spelling of 6431276640 in words is "six billion, four hundred thirty-one million, two hundred seventy-six thousand, six hundred forty".