66661896 has 96 divisors (see below), whose sum is σ = 202472640. Its totient is φ = 17912832.

The previous prime is 66661883. The next prime is 66661897. The reversal of 66661896 is 69816666.

It is a happy number.

66661896 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (66661897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47866 + ... + 49238.

It is an arithmetic number, because the mean of its divisors is an integer number (2109090).

Almost surely, 2^66661896 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 66661896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101236320).

66661896 is an abundant number, since it is smaller than the sum of its proper divisors (135810744).

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

66661896 is a wasteful number, since it uses less digits than its factorization.

66661896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423 (or 1402 counting only the distinct ones).

The product of its digits is 559872, while the sum is 48.

The square root of 66661896 is about 8164.6736615740. The cubic root of 66661896 is about 405.4704607547.

The spelling of 66661896 in words is "sixty-six million, six hundred sixty-one thousand, eight hundred ninety-six".