66535811837 has 16 divisors (see below), whose sum is σ = 74143060992. Its totient is φ = 59188812720.

The previous prime is 66535811813. The next prime is 66535811869. The reversal of 66535811837 is 73811853566.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66535811837 - 2¹⁴ = 66535795453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66535861837) 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, 3880838 + ... + 3897944.

It is an arithmetic number, because the mean of its divisors is an integer number (4633941312).

Almost surely, 2^66535811837 is an apocalyptic number.

It is an amenable number.

66535811837 is a deficient number, since it is larger than the sum of its proper divisors (7607249155).

66535811837 is a wasteful number, since it uses less digits than its factorization.

66535811837 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24688.

The product of its digits is 3628800, while the sum is 53.

The spelling of 66535811837 in words is "sixty-six billion, five hundred thirty-five million, eight hundred eleven thousand, eight hundred thirty-seven".