640643611053 has 4 divisors (see below), whose sum is σ = 854191481408. Its totient is φ = 427095740700.

The previous prime is 640643611043. The next prime is 640643611079. The reversal of 640643611053 is 350116346046.

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 not a de Polignac number, because 640643611053 - 2⁴ = 640643611037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640643611043) 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, 106773935173 + ... + 106773935178.

It is an arithmetic number, because the mean of its divisors is an integer number (213547870352).

Almost surely, 2^640643611053 is an apocalyptic number.

It is an amenable number.

640643611053 is a deficient number, since it is larger than the sum of its proper divisors (213547870355).

640643611053 is a wasteful number, since it uses less digits than its factorization.

640643611053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213547870354.

The product of its (nonzero) digits is 155520, while the sum is 39.

Adding to 640643611053 its reverse (350116346046), we get a palindrome (990759957099).

The spelling of 640643611053 in words is "six hundred forty billion, six hundred forty-three million, six hundred eleven thousand, fifty-three".