1661746 has 4 divisors (see below), whose sum is σ = 2492622. Its totient is φ = 830872.

The previous prime is 1661741. The next prime is 1661789. The reversal of 1661746 is 6471661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6471661 = 7 ⋅924523.

It can be written as a sum of positive squares in only one way, i.e., 1661521 + 225 = 1289^2 + 15^2 .

It is a super-2 number, since 2×1661746² = 5522799537032, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (1661741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415435 + ... + 415438.

2^1661746 is an apocalyptic number.

1661746 is a deficient number, since it is larger than the sum of its proper divisors (830876).

1661746 is an equidigital number, since it uses as much as digits as its factorization.

1661746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 830875.

The product of its digits is 6048, while the sum is 31.

The square root of 1661746 is about 1289.0872740044. The cubic root of 1661746 is about 118.4463132216.

The spelling of 1661746 in words is "one million, six hundred sixty-one thousand, seven hundred forty-six".