840356240 has 80 divisors (see below), whose sum is σ = 2112936192. Its totient is φ = 309614592.

The previous prime is 840356227. The next prime is 840356243. The reversal of 840356240 is 42653048.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×840356240² = 1412397220213875200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 840356197 and 840356206.

It is not an unprimeable number, because it can be changed into a prime (840356243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57347 + ... + 70493.

Almost surely, 2^840356240 is an apocalyptic number.

840356240 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 840356240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1056468096).

840356240 is an abundant number, since it is smaller than the sum of its proper divisors (1272579952).

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

840356240 is a wasteful number, since it uses less digits than its factorization.

840356240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13224 (or 13218 counting only the distinct ones).

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

The square root of 840356240 is about 28988.8985647955. The cubic root of 840356240 is about 943.6721606488.

The spelling of 840356240 in words is "eight hundred forty million, three hundred fifty-six thousand, two hundred forty".