825921540 has 108 divisors (see below), whose sum is σ = 2661502116. Its totient is φ = 207277056.

The previous prime is 825921539. The next prime is 825921611. The reversal of 825921540 is 45129528.

825921540 is a `hidden beast` number, since 8 + 25 + 92 + 1 + 540 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 270470916 + 555450624 = 16446^2 + 23568^2 .

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 = 825921495 and 825921504.

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, 44082 + ... + 59958.

Almost surely, 2^825921540 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 825921540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1330751058).

825921540 is an abundant number, since it is smaller than the sum of its proper divisors (1835580576).

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

825921540 is a wasteful number, since it uses less digits than its factorization.

825921540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15926 (or 15904 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 825921540 is about 28738.8507077092. The cubic root of 825921540 is about 938.2378106588.

The spelling of 825921540 in words is "eight hundred twenty-five million, nine hundred twenty-one thousand, five hundred forty".