64811671365544 has 8 divisors (see below), whose sum is σ = 121521883810410. Its totient is φ = 32405835682768.

The previous prime is 64811671365541. The next prime is 64811671365577. The reversal of 64811671365544 is 44556317611846.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 55035180844900 + 9776490520644 = 7418570^2 + 3126738^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (64811671365541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4050729460339 + ... + 4050729460354.

Almost surely, 2^{64811671365544} is an apocalyptic number.

It is an amenable number.

64811671365544 is a deficient number, since it is larger than the sum of its proper divisors (56710212444866).

64811671365544 is a wasteful number, since it uses less digits than its factorization.

64811671365544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8101458920699 (or 8101458920695 counting only the distinct ones).

The product of its digits is 58060800, while the sum is 61.

The spelling of 64811671365544 in words is "sixty-four trillion, eight hundred eleven billion, six hundred seventy-one million, three hundred sixty-five thousand, five hundred forty-four".