1665880900 has 72 divisors (see below), whose sum is σ = 3676709120. Its totient is φ = 655050240.

The previous prime is 1665880891. The next prime is 1665880913. The reversal of 1665880900 is 90885661.

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, 3420457 + ... + 3420943.

Almost surely, 2^1665880900 is an apocalyptic number.

1665880900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1665880900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1838354560).

1665880900 is an abundant number, since it is smaller than the sum of its proper divisors (2010828220).

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

1665880900 is a wasteful number, since it uses less digits than its factorization.

1665880900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013 (or 1006 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 43.

The square root of 1665880900 is about 40815.2042748778. The cubic root of 1665880900 is about 1185.4447463276. Note that the first 3 decimals are identical.

The spelling of 1665880900 in words is "one billion, six hundred sixty-five million, eight hundred eighty thousand, nine hundred".