666506100 has 72 divisors (see below), whose sum is σ = 2076776800. Its totient is φ = 164062080.

The previous prime is 666506041. The next prime is 666506189. The reversal of 666506100 is 1605666.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81550 + ... + 89349.

Almost surely, 2^666506100 is an apocalyptic number.

666506100 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

666506100 is an abundant number, since it is smaller than the sum of its proper divisors (1410270700).

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

666506100 is a wasteful number, since it uses less digits than its factorization.

666506100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170929 (or 170922 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 666506100 is about 25816.7794273414. The cubic root of 666506100 is about 873.5103251533.

The spelling of 666506100 in words is "six hundred sixty-six million, five hundred six thousand, one hundred".