851248640 has 320 divisors, whose sum is σ = 2463056640. Its totient is φ = 278691840.

The previous prime is 851248639. The next prime is 851248711. The reversal of 851248640 is 46842158.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 851248594 and 851248603.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19796459 + ... + 19796501.

It is an arithmetic number, because the mean of its divisors is an integer number (7697052).

Almost surely, 2^851248640 is an apocalyptic number.

851248640 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 851248640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1231528320).

851248640 is an abundant number, since it is smaller than the sum of its proper divisors (1611808000).

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

851248640 is a wasteful number, since it uses less digits than its factorization.

851248640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 38.

The square root of 851248640 is about 29176.1656151044. The cubic root of 851248640 is about 947.7318522103.

The spelling of 851248640 in words is "eight hundred fifty-one million, two hundred forty-eight thousand, six hundred forty".