825661440 has 432 divisors, whose sum is σ = 3137883840. Its totient is φ = 200540160.

The previous prime is 825661439. The next prime is 825661451. The reversal of 825661440 is 44166528.

825661440 is a `hidden beast` number, since 82 + 566 + 14 + 4 + 0 = 666.

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 = 825661395 and 825661404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 26634225 + ... + 26634255.

It is an arithmetic number, because the mean of its divisors is an integer number (7263620).

Almost surely, 2^825661440 is an apocalyptic number.

825661440 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 825661440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1568941920).

825661440 is an abundant number, since it is smaller than the sum of its proper divisors (2312222400).

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

825661440 is a wasteful number, since it uses less digits than its factorization.

825661440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 58 counting only the distinct ones).

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

The square root of 825661440 is about 28734.3251182275. The cubic root of 825661440 is about 938.1393100690.

It can be divided in two parts, 8256 and 61440, that added together give a palindrome (69696).

The spelling of 825661440 in words is "eight hundred twenty-five million, six hundred sixty-one thousand, four hundred forty".