640014060821 has 4 divisors (see below), whose sum is σ = 653631381312. Its totient is φ = 626396740332.

The previous prime is 640014060799. The next prime is 640014060857. The reversal of 640014060821 is 128060410046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640014060821 - 2¹⁴ = 640014044437 is a prime.

It is a super-3 number, since 3×640014060821³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640014060871) 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 in 3 ways as a sum of consecutive naturals, for example, 6808660175 + ... + 6808660268.

It is an arithmetic number, because the mean of its divisors is an integer number (163407845328).

Almost surely, 2^640014060821 is an apocalyptic number.

It is an amenable number.

640014060821 is a deficient number, since it is larger than the sum of its proper divisors (13617320491).

640014060821 is a wasteful number, since it uses less digits than its factorization.

640014060821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13617320490.

The product of its (nonzero) digits is 9216, while the sum is 32.

Adding to 640014060821 its reverse (128060410046), we get a palindrome (768074470867).

The spelling of 640014060821 in words is "six hundred forty billion, fourteen million, sixty thousand, eight hundred twenty-one".