400806144 has 216 divisors, whose sum is σ = 1272267360. Its totient is φ = 125411328.

The previous prime is 400806113. The next prime is 400806157. The reversal of 400806144 is 441608004.

400806144 is a `hidden beast` number, since 40 + 0 + 8 + 0 + 614 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (216).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1057347 + ... + 1057725.

Almost surely, 2^400806144 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 400806144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (636133680).

400806144 is an abundant number, since it is smaller than the sum of its proper divisors (871461216).

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

400806144 is an equidigital number, since it uses as much as digits as its factorization.

400806144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 401 counting only the distinct ones).

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

The square root of 400806144 is about 20020.1434560295. The cubic root of 400806144 is about 737.3009442292.

The spelling of 400806144 in words is "four hundred million, eight hundred six thousand, one hundred forty-four".