8251064640 has 672 divisors, whose sum is σ = 36790091520. Its totient is φ = 1648263168.

The previous prime is 8251064629. The next prime is 8251064641. The reversal of 8251064640 is 464601528.

8251064640 is a `hidden beast` number, since 8 + 2 + 5 + 1 + 0 + 6 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 8251064595 and 8251064604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8251064641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4978692 + ... + 4980348.

It is an arithmetic number, because the mean of its divisors is an integer number (54747160).

Almost surely, 2^8251064640 is an apocalyptic number.

8251064640 is a gapful number since it is divisible by the number (80) 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 8251064640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18395045760).

8251064640 is an abundant number, since it is smaller than the sum of its proper divisors (28539026880).

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

8251064640 is a wasteful number, since it uses less digits than its factorization.

8251064640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1719 (or 1706 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 8251064640 is about 90835.3710841762. The cubic root of 8251064640 is about 2020.7069250730.

The spelling of 8251064640 in words is "eight billion, two hundred fifty-one million, sixty-four thousand, six hundred forty".