64540960465581 has 48 divisors (see below), whose sum is σ = 95722953406080. Its totient is φ = 41881917127680.

The previous prime is 64540960465483. The next prime is 64540960465613. The reversal of 64540960465581 is 18556406904546.

64540960465581 is a `hidden beast` number, since 6 + 4 + 5 + 4 + 0 + 9 + 6 + 0 + 46 + 5 + 581 = 666.

64540960465581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 64540960465581 - 2¹¹ = 64540960463533 is a prime.

It is a super-2 number, since 2×64540960465581² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64540960465181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 145376661 + ... + 145819941.

It is an arithmetic number, because the mean of its divisors is an integer number (1994228195960).

Almost surely, 2^{64540960465581} is an apocalyptic number.

It is an amenable number.

64540960465581 is a deficient number, since it is larger than the sum of its proper divisors (31181992940499).

64540960465581 is a wasteful number, since it uses less digits than its factorization.

64540960465581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444626 (or 444623 counting only the distinct ones).

The product of its (nonzero) digits is 124416000, while the sum is 63.

The spelling of 64540960465581 in words is "sixty-four trillion, five hundred forty billion, nine hundred sixty million, four hundred sixty-five thousand, five hundred eighty-one".