1661888 has 28 divisors (see below), whose sum is σ = 3444240. Its totient is φ = 794112.

The previous prime is 1661887. The next prime is 1661893. The reversal of 1661888 is 8881661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 908 + ... + 2036.

2^1661888 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 1661888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1722120).

1661888 is an abundant number, since it is smaller than the sum of its proper divisors (1782352).

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

1661888 is a wasteful number, since it uses less digits than its factorization.

1661888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1164 (or 1154 counting only the distinct ones).

The product of its digits is 18432, while the sum is 38.

The square root of 1661888 is about 1289.1423505571. The cubic root of 1661888 is about 118.4496869617.

The spelling of 1661888 in words is "one million, six hundred sixty-one thousand, eight hundred eighty-eight".