209108302640 has 40 divisors (see below), whose sum is σ = 486324788400. Its totient is φ = 83617861376.

The previous prime is 209108302633. The next prime is 209108302651. The reversal of 209108302640 is 46203801902.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 209108302640.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132239 + ... + 660078.

It is an arithmetic number, because the mean of its divisors is an integer number (12158119710).

Almost surely, 2^209108302640 is an apocalyptic number.

209108302640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

209108302640 is an abundant number, since it is smaller than the sum of its proper divisors (277216485760).

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

209108302640 is a wasteful number, since it uses less digits than its factorization.

209108302640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795629 (or 795623 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The spelling of 209108302640 in words is "two hundred nine billion, one hundred eight million, three hundred two thousand, six hundred forty".