64138481641 has 4 divisors (see below), whose sum is σ = 69072211012. Its totient is φ = 59204752272.

The previous prime is 64138481629. The next prime is 64138481669. The reversal of 64138481641 is 14618483146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14618483146 = 2 ⋅7309241573.

It can be written as a sum of positive squares in 2 ways, for example, as 7534934416 + 56603547225 = 86804^2 + 237915^2 .

It is a cyclic number.

It is not a de Polignac number, because 64138481641 - 2⁹ = 64138481129 is a prime.

It is a super-2 number, since 2×64138481641² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64138481591 and 64138481600.

It is not an unprimeable number, because it can be changed into a prime (64138481611) 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, 2466864666 + ... + 2466864691.

It is an arithmetic number, because the mean of its divisors is an integer number (17268052753).

Almost surely, 2^64138481641 is an apocalyptic number.

It is an amenable number.

64138481641 is a deficient number, since it is larger than the sum of its proper divisors (4933729371).

64138481641 is a wasteful number, since it uses less digits than its factorization.

64138481641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4933729370.

The product of its digits is 442368, while the sum is 46.

The spelling of 64138481641 in words is "sixty-four billion, one hundred thirty-eight million, four hundred eighty-one thousand, six hundred forty-one".