851125640 has 48 divisors (see below), whose sum is σ = 1983423780. Its totient is φ = 328697600.

The previous prime is 851125637. The next prime is 851125643. The reversal of 851125640 is 46521158.

It is an interprime number because it is at equal distance from previous prime (851125637) and next prime (851125643).

It can be written as a sum of positive squares in 6 ways, for example, as 447999556 + 403126084 = 21166^2 + 20078^2 .

It is a junction number, because it is equal to n+sod(n) for n = 851125597 and 851125606.

It is not an unprimeable number, because it can be changed into a prime (851125643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20990 + ... + 46290.

Almost surely, 2^851125640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 851125640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (991711890).

851125640 is an abundant number, since it is smaller than the sum of its proper divisors (1132298140).

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

851125640 is a wasteful number, since it uses less digits than its factorization.

851125640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25370 (or 25337 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 851125640 is about 29174.0576540186. The cubic root of 851125640 is about 947.6862029419.

Adding to 851125640 its reverse (46521158), we get a palindrome (897646798).

The spelling of 851125640 in words is "eight hundred fifty-one million, one hundred twenty-five thousand, six hundred forty".