840805252440 has 32 divisors (see below), whose sum is σ = 2522415757680. Its totient is φ = 224214733952.

The previous prime is 840805252439. The next prime is 840805252457. The reversal of 840805252440 is 44252508048.

It is a junction number, because it is equal to n+sod(n) for n = 840805252392 and 840805252401.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3503355099 + ... + 3503355338.

Almost surely, 2^840805252440 is an apocalyptic number.

It is an amenable number.

840805252440 is an abundant number, since it is smaller than the sum of its proper divisors (1681610505240).

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

840805252440 is a wasteful number, since it uses less digits than its factorization.

840805252440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7006710451 (or 7006710447 counting only the distinct ones).

The product of its (nonzero) digits is 409600, while the sum is 42.

The spelling of 840805252440 in words is "eight hundred forty billion, eight hundred five million, two hundred fifty-two thousand, four hundred forty".