640322553612261 has 8 divisors (see below), whose sum is σ = 919437512879200. Its totient is φ = 394044648376752.

The previous prime is 640322553612221. The next prime is 640322553612277. The reversal of 640322553612261 is 162216355223046.

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

It is not a de Polignac number, because 640322553612261 - 2²³ = 640322545223653 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640322553612261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640322553612221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8209263507811 + ... + 8209263507888.

It is an arithmetic number, because the mean of its divisors is an integer number (114929689109900).

Almost surely, 2^{640322553612261} is an apocalyptic number.

It is an amenable number.

640322553612261 is a deficient number, since it is larger than the sum of its proper divisors (279114959266939).

640322553612261 is a wasteful number, since it uses less digits than its factorization.

640322553612261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16418527015715.

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 640322553612261 in words is "six hundred forty trillion, three hundred twenty-two billion, five hundred fifty-three million, six hundred twelve thousand, two hundred sixty-one".