64439366381 has 16 divisors (see below), whose sum is σ = 73538976000. Its totient is φ = 55973602368.

The previous prime is 64439366357. The next prime is 64439366401. The reversal of 64439366381 is 18366393446.

It is a happy number.

64439366381 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 64439366381 - 2²² = 64435172077 is a prime.

It is a super-5 number, since 5×64439366381⁵ (a number of 55 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64439366351) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 838661 + ... + 912266.

It is an arithmetic number, because the mean of its divisors is an integer number (4596186000).

Almost surely, 2^64439366381 is an apocalyptic number.

It is an amenable number.

64439366381 is a deficient number, since it is larger than the sum of its proper divisors (9099609619).

64439366381 is a wasteful number, since it uses less digits than its factorization.

64439366381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751108.

The product of its digits is 6718464, while the sum is 53.

The spelling of 64439366381 in words is "sixty-four billion, four hundred thirty-nine million, three hundred sixty-six thousand, three hundred eighty-one".