840236540 has 96 divisors (see below), whose sum is σ = 2096902080. Its totient is φ = 278784000.

The previous prime is 840236533. The next prime is 840236567. The reversal of 840236540 is 45632048.

It is a junction number, because it is equal to n+sod(n) for n = 840236497 and 840236506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 252890 + ... + 256190.

It is an arithmetic number, because the mean of its divisors is an integer number (21842730).

Almost surely, 2^840236540 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 840236540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1048451040).

840236540 is an abundant number, since it is smaller than the sum of its proper divisors (1256665540).

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

840236540 is a wasteful number, since it uses less digits than its factorization.

840236540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3423 (or 3421 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 840236540 is about 28986.8339078279. The cubic root of 840236540 is about 943.6273530954.

Adding to 840236540 its reverse (45632048), we get a palindrome (885868588).

The spelling of 840236540 in words is "eight hundred forty million, two hundred thirty-six thousand, five hundred forty".