66474542656 has 84 divisors (see below), whose sum is σ = 134051538348. Its totient is φ = 32705609728.

The previous prime is 66474542599. The next prime is 66474542749. The reversal of 66474542656 is 65624547466.

It can be written as a sum of positive squares in 2 ways, for example, as 51068768256 + 15405774400 = 225984^2 + 124120^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66474542597 and 66474542606.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 188312976 + ... + 188313328.

It is an arithmetic number, because the mean of its divisors is an integer number (1595851647).

Almost surely, 2^66474542656 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 66474542656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67025769174).

66474542656 is an abundant number, since it is smaller than the sum of its proper divisors (67576995692).

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

66474542656 is a wasteful number, since it uses less digits than its factorization.

66474542656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836 (or 719 counting only the distinct ones).

The product of its digits is 29030400, while the sum is 55.

The spelling of 66474542656 in words is "sixty-six billion, four hundred seventy-four million, five hundred forty-two thousand, six hundred fifty-six".