1666695888 has 240 divisors, whose sum is σ = 5670887040. Its totient is φ = 449971200.

The previous prime is 1666695887. The next prime is 1666695893. The reversal of 1666695888 is 8885966661.

It is a super-2 number, since 2×1666695888² = 5555750366152217088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666695887) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 595773 + ... + 598563.

It is an arithmetic number, because the mean of its divisors is an integer number (23628696).

Almost surely, 2^1666695888 is an apocalyptic number.

1666695888 is a gapful number since it is divisible by the number (18) 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 1666695888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2835443520).

1666695888 is an abundant number, since it is smaller than the sum of its proper divisors (4004191152).

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

1666695888 is a wasteful number, since it uses less digits than its factorization.

1666695888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2858 (or 2849 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 63.

The square root of 1666695888 is about 40825.1869315990. The cubic root of 1666695888 is about 1185.6380306005.

The spelling of 1666695888 in words is "one billion, six hundred sixty-six million, six hundred ninety-five thousand, eight hundred eighty-eight".