640434105634 has 8 divisors (see below), whose sum is σ = 986614703388. Its totient is φ = 311562537840.

The previous prime is 640434105617. The next prime is 640434105679. The reversal of 640434105634 is 436501434046.

It can be written as a sum of positive squares in 2 ways, for example, as 640408065025 + 26040609 = 800255^2 + 5103^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×640434105634³ (a number of 36 digits) contains 333 as substring.

It is an unprimeable number.

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, 4327257397 + ... + 4327257544.

Almost surely, 2^640434105634 is an apocalyptic number.

640434105634 is a deficient number, since it is larger than the sum of its proper divisors (346180597754).

640434105634 is a wasteful number, since it uses less digits than its factorization.

640434105634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8654514980.

The product of its (nonzero) digits is 414720, while the sum is 40.

The spelling of 640434105634 in words is "six hundred forty billion, four hundred thirty-four million, one hundred five thousand, six hundred thirty-four".