640640160001 has 4 divisors (see below), whose sum is σ = 640654523604. Its totient is φ = 640625796400.

The previous prime is 640640159989. The next prime is 640640160007. The reversal of 640640160001 is 100061046046.

It is a Cunningham number, because it is equal to 800400²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2317459600 + 638322700401 = 48140^2 + 798951^2 .

It is a cyclic number.

It is not a de Polignac number, because 640640160001 - 2²³ = 640631771393 is a prime.

It is a super-2 number, since 2×640640160001² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640640160007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7114690 + ... + 7204171.

It is an arithmetic number, because the mean of its divisors is an integer number (160163630901).

Almost surely, 2^640640160001 is an apocalyptic number.

It is an amenable number.

640640160001 is a deficient number, since it is larger than the sum of its proper divisors (14363603).

640640160001 is a wasteful number, since it uses less digits than its factorization.

640640160001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14363602.

The product of its (nonzero) digits is 3456, while the sum is 28.

The spelling of 640640160001 in words is "six hundred forty billion, six hundred forty million, one hundred sixty thousand, one".