840473991 has 24 divisors (see below), whose sum is σ = 1388944544. Its totient is φ = 479753280.

The previous prime is 840473983. The next prime is 840474007. The reversal of 840473991 is 199374048.

It is not a de Polignac number, because 840473991 - 2³ = 840473983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840473941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56121 + ... + 69501.

Almost surely, 2^840473991 is an apocalyptic number.

840473991 is a deficient number, since it is larger than the sum of its proper divisors (548470553).

840473991 is a wasteful number, since it uses less digits than its factorization.

840473991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14391 (or 14388 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 840473991 is about 28990.9294607813. The cubic root of 840473991 is about 943.7162344775.

The spelling of 840473991 in words is "eight hundred forty million, four hundred seventy-three thousand, nine hundred ninety-one".