66156556 has 24 divisors (see below), whose sum is σ = 127169280. Its totient is φ = 29974032.

The previous prime is 66156551. The next prime is 66156557. The reversal of 66156556 is 65565166.

66156556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66156556² = 8753379803562272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66156551) 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 7 ways as a sum of consecutive naturals, for example, 17176 + ... + 20671.

It is an arithmetic number, because the mean of its divisors is an integer number (5298720).

Almost surely, 2^66156556 is an apocalyptic number.

It is an amenable number.

66156556 is a deficient number, since it is larger than the sum of its proper divisors (61012724).

66156556 is a wasteful number, since it uses less digits than its factorization.

66156556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37893 (or 37891 counting only the distinct ones).

The product of its digits is 162000, while the sum is 40.

The square root of 66156556 is about 8133.6680532217. The cubic root of 66156556 is about 404.4432852838.

The spelling of 66156556 in words is "sixty-six million, one hundred fifty-six thousand, five hundred fifty-six".