1661838 has 16 divisors (see below), whose sum is σ = 3344976. Its totient is φ = 550400.

The previous prime is 1661833. The next prime is 1661839. The reversal of 1661838 is 8381661.

It is a junction number, because it is equal to n+sod(n) for n = 1661799 and 1661808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 238 + ... + 1838.

It is an arithmetic number, because the mean of its divisors is an integer number (209061).

2^1661838 is an apocalyptic number.

1661838 is an abundant number, since it is smaller than the sum of its proper divisors (1683138).

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

1661838 is a wasteful number, since it uses less digits than its factorization.

1661838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1779.

The product of its digits is 6912, while the sum is 33.

The square root of 1661838 is about 1289.1229576732. The cubic root of 1661838 is about 118.4484990470.

The spelling of 1661838 in words is "one million, six hundred sixty-one thousand, eight hundred thirty-eight".