66521104 has 60 divisors (see below), whose sum is σ = 141893076. Its totient is φ = 30191616.

The previous prime is 66521101. The next prime is 66521113. The reversal of 66521104 is 40112566.

It can be written as a sum of positive squares in 6 ways, for example, as 13987600 + 52533504 = 3740^2 + 7248^2 .

It is not an unprimeable number, because it can be changed into a prime (66521101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 197224 + ... + 197560.

Almost surely, 2^66521104 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66521104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70946538).

66521104 is an abundant number, since it is smaller than the sum of its proper divisors (75371972).

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

66521104 is a wasteful number, since it uses less digits than its factorization.

66521104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444 (or 425 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 66521104 is about 8156.0470817670. The cubic root of 66521104 is about 405.1848041423.

The spelling of 66521104 in words is "sixty-six million, five hundred twenty-one thousand, one hundred four".