812125440 has 432 divisors, whose sum is σ = 3339143808. Its totient is φ = 185131008.

The previous prime is 812125429. The next prime is 812125441. The reversal of 812125440 is 44521218.

812125440 is a `hidden beast` number, since 8 + 1 + 212 + 5 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812125441) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2177094 + ... + 2177466.

Almost surely, 2^812125440 is an apocalyptic number.

812125440 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 812125440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1669571904).

812125440 is an abundant number, since it is smaller than the sum of its proper divisors (2527018368).

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

812125440 is an equidigital number, since it uses as much as digits as its factorization.

812125440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 812125440 is about 28497.8146530572. The cubic root of 812125440 is about 932.9843774847.

Adding to 812125440 its reverse (44521218), we get a palindrome (856646658).

The spelling of 812125440 in words is "eight hundred twelve million, one hundred twenty-five thousand, four hundred forty".