64534527821 has 16 divisors (see below), whose sum is σ = 65478663360. Its totient is φ = 63597139200.

The previous prime is 64534527817. The next prime is 64534527847. The reversal of 64534527821 is 12872543546.

It is a cyclic number.

It is not a de Polignac number, because 64534527821 - 2² = 64534527817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64534523821) 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, 22698026 + ... + 22700868.

It is an arithmetic number, because the mean of its divisors is an integer number (4092416460).

Almost surely, 2^64534527821 is an apocalyptic number.

It is an amenable number.

64534527821 is a deficient number, since it is larger than the sum of its proper divisors (944135539).

64534527821 is a wasteful number, since it uses less digits than its factorization.

64534527821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3916.

The product of its digits is 1612800, while the sum is 47.

The spelling of 64534527821 in words is "sixty-four billion, five hundred thirty-four million, five hundred twenty-seven thousand, eight hundred twenty-one".