840709581440 has 64 divisors (see below), whose sum is σ = 2011507848360. Its totient is φ = 336001646592.

The previous prime is 840709581407. The next prime is 840709581473. The reversal of 840709581440 is 44185907048.

It is an interprime number because it is at equal distance from previous prime (840709581407) and next prime (840709581473).

It can be written as a sum of positive squares in 4 ways, for example, as 458914114624 + 381795466816 = 677432^2 + 617896^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212972 + ... + 1314068.

Almost surely, 2^840709581440 is an apocalyptic number.

840709581440 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 840709581440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1005753924180).

840709581440 is an abundant number, since it is smaller than the sum of its proper divisors (1170798266920).

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

840709581440 is a wasteful number, since it uses less digits than its factorization.

840709581440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1102309 (or 1102297 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 50.

The spelling of 840709581440 in words is "eight hundred forty billion, seven hundred nine million, five hundred eighty-one thousand, four hundred forty".