640070400 has 432 divisors, whose sum is σ = 2340412704. Its totient is φ = 153354240.

The previous prime is 640070371. The next prime is 640070401. The reversal of 640070400 is 4070046.

It is not an unprimeable number, because it can be changed into a prime (640070401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 12076774 + ... + 12076826.

It is an arithmetic number, because the mean of its divisors is an integer number (5417622).

Almost surely, 2^640070400 is an apocalyptic number.

640070400 is a gapful number since it is divisible by the number (60) 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 640070400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1170206352).

640070400 is an abundant number, since it is smaller than the sum of its proper divisors (1700342304).

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

640070400 is a wasteful number, since it uses less digits than its factorization.

640070400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 640070400 is about 25299.6126452561. The cubic root of 640070400 is about 861.8054732297.

The spelling of 640070400 in words is "six hundred forty million, seventy thousand, four hundred".