640642503431 has 16 divisors (see below), whose sum is σ = 775304789760. Its totient is φ = 516771826560.

The previous prime is 640642503419. The next prime is 640642503437. The reversal of 640642503431 is 134305246046.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640642503431 is a prime.

It is a super-2 number, since 2×640642503431² (a number of 24 digits) contains 22 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 (640642503437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1031840 + ... + 1531658.

It is an arithmetic number, because the mean of its divisors is an integer number (48456549360).

Almost surely, 2^640642503431 is an apocalyptic number.

640642503431 is a deficient number, since it is larger than the sum of its proper divisors (134662286329).

640642503431 is a wasteful number, since it uses less digits than its factorization.

640642503431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510614.

The product of its (nonzero) digits is 207360, while the sum is 38.

Adding to 640642503431 its reverse (134305246046), we get a palindrome (774947749477).

The spelling of 640642503431 in words is "six hundred forty billion, six hundred forty-two million, five hundred three thousand, four hundred thirty-one".