1661938 has 8 divisors (see below), whose sum is σ = 2501100. Its totient is φ = 828240.

The previous prime is 1661917. The next prime is 1661939. The reversal of 1661938 is 8391661.

It can be written as a sum of positive squares in 2 ways, for example, as 1555009 + 106929 = 1247^2 + 327^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (1661939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 493 + ... + 1888.

2^1661938 is an apocalyptic number.

1661938 is a deficient number, since it is larger than the sum of its proper divisors (839162).

1661938 is a wasteful number, since it uses less digits than its factorization.

1661938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2732.

The product of its digits is 7776, while the sum is 34.

The square root of 1661938 is about 1289.1617431494. The cubic root of 1661938 is about 118.4508748526.

The spelling of 1661938 in words is "one million, six hundred sixty-one thousand, nine hundred thirty-eight".