640609276 has 6 divisors (see below), whose sum is σ = 1121066240. Its totient is φ = 320304636.

The previous prime is 640609261. The next prime is 640609279. The reversal of 640609276 is 672906046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640609279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80076156 + ... + 80076163.

Almost surely, 2^640609276 is an apocalyptic number.

It is an amenable number.

640609276 is a deficient number, since it is larger than the sum of its proper divisors (480456964).

640609276 is a wasteful number, since it uses less digits than its factorization.

640609276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160152323 (or 160152321 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 40.

The square root of 640609276 is about 25310.2602910361. The cubic root of 640609276 is about 862.0472570600.

The spelling of 640609276 in words is "six hundred forty million, six hundred nine thousand, two hundred seventy-six".