66505554 has 48 divisors (see below), whose sum is σ = 146928600. Its totient is φ = 21738240.

The previous prime is 66505531. The next prime is 66505559. The reversal of 66505554 is 45550566.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25250625 + 41254929 = 5025^2 + 6423^2 .

It is not an unprimeable number, because it can be changed into a prime (66505559) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 367344 + ... + 367524.

Almost surely, 2^66505554 is an apocalyptic number.

66505554 is an abundant number, since it is smaller than the sum of its proper divisors (80423046).

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

66505554 is a wasteful number, since it uses less digits than its factorization.

66505554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 475 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The square root of 66505554 is about 8155.0937456292. The cubic root of 66505554 is about 405.1532296277.

The spelling of 66505554 in words is "sixty-six million, five hundred five thousand, five hundred fifty-four".