640239009644 has 12 divisors (see below), whose sum is σ = 1206604287504. Its totient is φ = 295494927504.

The previous prime is 640239009637. The next prime is 640239009659. The reversal of 640239009644 is 446900932046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6156144272 + ... + 6156144375.

It is an arithmetic number, because the mean of its divisors is an integer number (100550357292).

Almost surely, 2^640239009644 is an apocalyptic number.

It is an amenable number.

640239009644 is a deficient number, since it is larger than the sum of its proper divisors (566365277860).

640239009644 is a wasteful number, since it uses less digits than its factorization.

640239009644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12312288664 (or 12312288662 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 47.

The spelling of 640239009644 in words is "six hundred forty billion, two hundred thirty-nine million, nine thousand, six hundred forty-four".