840401406 has 112 divisors (see below), whose sum is σ = 2060261280. Its totient is φ = 255441600.

The previous prime is 840401389. The next prime is 840401437. The reversal of 840401406 is 604104048.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 840401406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 1914135 + ... + 1914573.

It is an arithmetic number, because the mean of its divisors is an integer number (18395190).

Almost surely, 2^840401406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 840401406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1030130640).

840401406 is an abundant number, since it is smaller than the sum of its proper divisors (1219859874).

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

840401406 is a wasteful number, since it uses less digits than its factorization.

840401406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573 (or 558 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 840401406 is about 28989.6775766824. The cubic root of 840401406 is about 943.6890666271.

The spelling of 840401406 in words is "eight hundred forty million, four hundred one thousand, four hundred six".