640837209601 has 4 divisors (see below), whose sum is σ = 641489130432. Its totient is φ = 640185288772.

The previous prime is 640837209559. The next prime is 640837209611. The reversal of 640837209601 is 106902738046.

640837209601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 640837209601 - 2¹³ = 640837201409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640837209611) 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, 325958941 + ... + 325960906.

It is an arithmetic number, because the mean of its divisors is an integer number (160372282608).

Almost surely, 2^640837209601 is an apocalyptic number.

It is an amenable number.

640837209601 is a deficient number, since it is larger than the sum of its proper divisors (651920831).

640837209601 is an equidigital number, since it uses as much as digits as its factorization.

640837209601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651920830.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 640837209601 in words is "six hundred forty billion, eight hundred thirty-seven million, two hundred nine thousand, six hundred one".