840561129408 has 896 divisors, whose sum is σ = 3048542300160. Its totient is φ = 197366906880.

The previous prime is 840561129407. The next prime is 840561129413. The reversal of 840561129408 is 804921165048.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840561129407) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2685498660 + ... + 2685498972.

It is an arithmetic number, because the mean of its divisors is an integer number (3402390960).

Almost surely, 2^840561129408 is an apocalyptic number.

840561129408 is a gapful number since it is divisible by the number (88) 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 840561129408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1524271150080).

840561129408 is an abundant number, since it is smaller than the sum of its proper divisors (2207981170752).

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

840561129408 is a wasteful number, since it uses less digits than its factorization.

840561129408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605 (or 595 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 48.

It can be divided in two parts, 840561 and 129408, that added together give a palindrome (969969).

The spelling of 840561129408 in words is "eight hundred forty billion, five hundred sixty-one million, one hundred twenty-nine thousand, four hundred eight".