404187840 has 448 divisors, whose sum is σ = 1679569920. Its totient is φ = 89579520.

The previous prime is 404187821. The next prime is 404187841. The reversal of 404187840 is 48781404.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 404187795 and 404187804.

It is not an unprimeable number, because it can be changed into a prime (404187841) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2479599 + ... + 2479761.

It is an arithmetic number, because the mean of its divisors is an integer number (3749040).

Almost surely, 2^404187840 is an apocalyptic number.

404187840 is a gapful number since it is divisible by the number (40) 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 404187840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (839784960).

404187840 is an abundant number, since it is smaller than the sum of its proper divisors (1275382080).

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

404187840 is a wasteful number, since it uses less digits than its factorization.

404187840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The square root of 404187840 is about 20104.4233938703. The cubic root of 404187840 is about 739.3687336180.

The spelling of 404187840 in words is "four hundred four million, one hundred eighty-seven thousand, eight hundred forty".