640378060 has 72 divisors (see below), whose sum is σ = 1570559760. Its totient is φ = 218687616.

The previous prime is 640378021. The next prime is 640378073. The reversal of 640378060 is 60873046.

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, 276186 + ... + 278494.

It is an arithmetic number, because the mean of its divisors is an integer number (21813330).

Almost surely, 2^640378060 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 640378060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785279880).

640378060 is an abundant number, since it is smaller than the sum of its proper divisors (930181700).

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

640378060 is a wasteful number, since it uses less digits than its factorization.

640378060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2615 (or 2606 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 640378060 is about 25305.6922450266. The cubic root of 640378060 is about 861.9435312732.

The spelling of 640378060 in words is "six hundred forty million, three hundred seventy-eight thousand, sixty".