1661929 has 4 divisors (see below), whose sum is σ = 1706884. Its totient is φ = 1616976.

The previous prime is 1661917. The next prime is 1661939. The reversal of 1661929 is 9291661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9291661 = 31 ⋅299731.

It can be written as a sum of positive squares in 2 ways, for example, as 851929 + 810000 = 923^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661929 - 2¹¹ = 1659881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1661894 and 1661903.

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, 22422 + ... + 22495.

It is an arithmetic number, because the mean of its divisors is an integer number (426721).

2^1661929 is an apocalyptic number.

It is an amenable number.

1661929 is a deficient number, since it is larger than the sum of its proper divisors (44955).

1661929 is an equidigital number, since it uses as much as digits as its factorization.

1661929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44954.

The product of its digits is 5832, while the sum is 34.

The square root of 1661929 is about 1289.1582525043. The cubic root of 1661929 is about 118.4506610340.

The spelling of 1661929 in words is "one million, six hundred sixty-one thousand, nine hundred twenty-nine".