640009796 has 6 divisors (see below), whose sum is σ = 1120017150. Its totient is φ = 320004896.

The previous prime is 640009771. The next prime is 640009819. The reversal of 640009796 is 697900046.

It can be written as a sum of positive squares in only one way, i.e., 608312896 + 31696900 = 24664^2 + 5630^2 .

It is a super-2 number, since 2×640009796² = 819225077951923232, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80001221 + ... + 80001228.

It is an arithmetic number, because the mean of its divisors is an integer number (186669525).

Almost surely, 2^640009796 is an apocalyptic number.

It is an amenable number.

640009796 is a deficient number, since it is larger than the sum of its proper divisors (480007354).

640009796 is a wasteful number, since it uses less digits than its factorization.

640009796 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160002453 (or 160002451 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 640009796 is about 25298.4148910559. The cubic root of 640009796 is about 861.7782728325.

The spelling of 640009796 in words is "six hundred forty million, nine thousand, seven hundred ninety-six".