64581708394943 has 4 divisors (see below), whose sum is σ = 64916328645888. Its totient is φ = 64247088144000.

The previous prime is 64581708394837. The next prime is 64581708394979. The reversal of 64581708394943 is 34949380718546.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64581708394943 - 2²² = 64581704200639 is a prime.

It is a super-2 number, since 2×64581708394943² (a number of 28 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 (64581708304943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167310125183 + ... + 167310125568.

It is an arithmetic number, because the mean of its divisors is an integer number (16229082161472).

Almost surely, 2^{64581708394943} is an apocalyptic number.

64581708394943 is a deficient number, since it is larger than the sum of its proper divisors (334620250945).

64581708394943 is a wasteful number, since it uses less digits than its factorization.

64581708394943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334620250944.

The product of its (nonzero) digits is 627056640, while the sum is 71.

The spelling of 64581708394943 in words is "sixty-four trillion, five hundred eighty-one billion, seven hundred eight million, three hundred ninety-four thousand, nine hundred forty-three".