666156100 has 81 divisors (see below), whose sum is σ = 1514135077. Its totient is φ = 254383360.

The previous prime is 666156097. The next prime is 666156109. The reversal of 666156100 is 1651666.

The square root of 666156100 is 25810.

It is a perfect power (a square), and thus also a powerful number.

666156100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 13 ways, for example, as 593701956 + 72454144 = 24366^2 + 8512^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666156109) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7484856 + ... + 7484944.

Almost surely, 2^666156100 is an apocalyptic number.

666156100 is the 25810-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666156100

666156100 is an abundant number, since it is smaller than the sum of its proper divisors (847978977).

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

666156100 is a wasteful number, since it uses less digits than its factorization.

666156100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The cubic root of 666156100 is about 873.3573972482.

The spelling of 666156100 in words is "six hundred sixty-six million, one hundred fifty-six thousand, one hundred".