1665204880 has 40 divisors (see below), whose sum is σ = 3944660472. Its totient is φ = 653512704.

The previous prime is 1665204851. The next prime is 1665204907. The reversal of 1665204880 is 884025661.

It can be written as a sum of positive squares in 4 ways, for example, as 112529664 + 1552675216 = 10608^2 + 39404^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 192129 + ... + 200608.

Almost surely, 2^1665204880 is an apocalyptic number.

1665204880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665204880 is an abundant number, since it is smaller than the sum of its proper divisors (2279455592).

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

1665204880 is a wasteful number, since it uses less digits than its factorization.

1665204880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392803 (or 392797 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 1665204880 is about 40806.9219618437. The cubic root of 1665204880 is about 1185.2843721609.

The spelling of 1665204880 in words is "one billion, six hundred sixty-five million, two hundred four thousand, eight hundred eighty".