640894630 has 8 divisors (see below), whose sum is σ = 1153610352. Its totient is φ = 256357848.

The previous prime is 640894627. The next prime is 640894637. The reversal of 640894630 is 36498046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640894637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32044722 + ... + 32044741.

It is an arithmetic number, because the mean of its divisors is an integer number (144201294).

Almost surely, 2^640894630 is an apocalyptic number.

640894630 is a deficient number, since it is larger than the sum of its proper divisors (512715722).

640894630 is a wasteful number, since it uses less digits than its factorization.

640894630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64089470.

The product of its (nonzero) digits is 124416, while the sum is 40.

The square root of 640894630 is about 25315.8967844317. The cubic root of 640894630 is about 862.1752352868.

The spelling of 640894630 in words is "six hundred forty million, eight hundred ninety-four thousand, six hundred thirty".