400081536 has 192 divisors, whose sum is σ = 1260230400. Its totient is φ = 121282560.

The previous prime is 400081529. The next prime is 400081547. The reversal of 400081536 is 635180004.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 606775 + ... + 607433.

It is an arithmetic number, because the mean of its divisors is an integer number (6563700).

Almost surely, 2^400081536 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 400081536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (630115200).

400081536 is an abundant number, since it is smaller than the sum of its proper divisors (860148864).

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

400081536 is a wasteful number, since it uses less digits than its factorization.

400081536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727 (or 712 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 400081536 is about 20002.0382961337. The cubic root of 400081536 is about 736.8563598589.

The spelling of 400081536 in words is "four hundred million, eighty-one thousand, five hundred thirty-six".