1665671000 has 128 divisors (see below), whose sum is σ = 4487184000. Its totient is φ = 566899200.

The previous prime is 1665670991. The next prime is 1665671009. The reversal of 1665671000 is 1765661.

It is an interprime number because it is at equal distance from previous prime (1665670991) and next prime (1665671009).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665671009) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1042202 + ... + 1043798.

It is an arithmetic number, because the mean of its divisors is an integer number (35056125).

Almost surely, 2^1665671000 is an apocalyptic number.

1665671000 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 1665671000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2243592000).

1665671000 is an abundant number, since it is smaller than the sum of its proper divisors (2821513000).

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

1665671000 is a wasteful number, since it uses less digits than its factorization.

1665671000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1774 (or 1760 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 1665671000 is about 40812.6328481758. The cubic root of 1665671000 is about 1185.3949557926.

The spelling of 1665671000 in words is "one billion, six hundred sixty-five million, six hundred seventy-one thousand".