400040064 has 48 divisors (see below), whose sum is σ = 1151160270. Its totient is φ = 133346304.

The previous prime is 400040063. The next prime is 400040099. The reversal of 400040064 is 460040004.

It can be written as a sum of positive squares in only one way, i.e., 399680064 + 360000 = 19992^2 + 600^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (400040063) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 172477 + ... + 174780.

Almost surely, 2^400040064 is an apocalyptic number.

It is an amenable number.

400040064 is an abundant number, since it is smaller than the sum of its proper divisors (751120206).

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

400040064 is a wasteful number, since it uses less digits than its factorization.

400040064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347277 (or 347262 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 400040064 is about 20001.0015749212. The cubic root of 400040064 is about 736.8308984132.

Adding to 400040064 its reverse (460040004), we get a palindrome (860080068).

The spelling of 400040064 in words is "four hundred million, forty thousand, sixty-four".