66542431326 has 16 divisors (see below), whose sum is σ = 152096985984. Its totient is φ = 19012123224.

The previous prime is 66542431273. The next prime is 66542431327. The reversal of 66542431326 is 62313424566.

It is a happy number.

It is a super-2 number, since 2×66542431326² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 1584343603 = 66542431326 / (6 + 6 + 5 + 4 + 2 + 4 + 3 + 1 + 3 + 2 + 6).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66542431327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 792171760 + ... + 792171843.

It is an arithmetic number, because the mean of its divisors is an integer number (9506061624).

Almost surely, 2^66542431326 is an apocalyptic number.

66542431326 is an abundant number, since it is smaller than the sum of its proper divisors (85554554658).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66542431326 is a wasteful number, since it uses less digits than its factorization.

66542431326 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1584343615.

The product of its digits is 622080, while the sum is 42.

The spelling of 66542431326 in words is "sixty-six billion, five hundred forty-two million, four hundred thirty-one thousand, three hundred twenty-six".