664540627634 has 16 divisors (see below), whose sum is σ = 1078095963672. Its totient is φ = 305394699648.

The previous prime is 664540627613. The next prime is 664540627693. The reversal of 664540627634 is 436726045466.

664540627634 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 335756508025 + 328784119609 = 579445^2 + 573397^2 .

It is a super-2 number, since 2×664540627634² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54842129 + ... + 54854244.

Almost surely, 2^664540627634 is an apocalyptic number.

664540627634 is a deficient number, since it is larger than the sum of its proper divisors (413555336038).

664540627634 is a wasteful number, since it uses less digits than its factorization.

664540627634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109696621.

The product of its (nonzero) digits is 17418240, while the sum is 53.

The spelling of 664540627634 in words is "six hundred sixty-four billion, five hundred forty million, six hundred twenty-seven thousand, six hundred thirty-four".