660405100 has 72 divisors (see below), whose sum is σ = 1464121568. Its totient is φ = 258508800.

The previous prime is 660405091. The next prime is 660405127. The reversal of 660405100 is 1504066.

It is a super-2 number, since 2×660405100² = 872269792212020000, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 998770 + ... + 999430.

Almost surely, 2^660405100 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 660405100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (732060784).

660405100 is an abundant number, since it is smaller than the sum of its proper divisors (803716468).

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

660405100 is a wasteful number, since it uses less digits than its factorization.

660405100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 875 (or 868 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 660405100 is about 25698.3481959444. The cubic root of 660405100 is about 870.8368659508.

Adding to 660405100 its reverse (1504066), we get a palindrome (661909166).

The spelling of 660405100 in words is "six hundred sixty million, four hundred five thousand, one hundred".