64520531738 has 16 divisors (see below), whose sum is σ = 107819457480. Its totient is φ = 28751854656.

The previous prime is 64520531731. The next prime is 64520531743. The reversal of 64520531738 is 83713502546.

It can be written as a sum of positive squares in 4 ways, for example, as 34679005729 + 29841526009 = 186223^2 + 172747^2 .

It is not an unprimeable number, because it can be changed into a prime (64520531731) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 42784745 + ... + 42786252.

Almost surely, 2^64520531738 is an apocalyptic number.

64520531738 is a deficient number, since it is larger than the sum of its proper divisors (43298925742).

64520531738 is a wasteful number, since it uses less digits than its factorization.

64520531738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85571041.

The product of its (nonzero) digits is 604800, while the sum is 44.

The spelling of 64520531738 in words is "sixty-four billion, five hundred twenty million, five hundred thirty-one thousand, seven hundred thirty-eight".