640468280181 has 8 divisors (see below), whose sum is σ = 873817188640. Its totient is φ = 417049112592.

The previous prime is 640468280159. The next prime is 640468280233. The reversal of 640468280181 is 181082864046.

It is a happy number.

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

It is not a de Polignac number, because 640468280181 - 2¹¹ = 640468278133 is a prime.

It is a super-2 number, since 2×640468280181² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 640468280181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640468280581) 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, 2482435066 + ... + 2482435323.

It is an arithmetic number, because the mean of its divisors is an integer number (109227148580).

Almost surely, 2^640468280181 is an apocalyptic number.

It is an amenable number.

640468280181 is a deficient number, since it is larger than the sum of its proper divisors (233348908459).

640468280181 is a wasteful number, since it uses less digits than its factorization.

640468280181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4964870435.

The product of its (nonzero) digits is 589824, while the sum is 48.

The spelling of 640468280181 in words is "six hundred forty billion, four hundred sixty-eight million, two hundred eighty thousand, one hundred eighty-one".