1661123 has 2 divisors, whose sum is σ = 1661124. Its totient is φ = 1661122.

The previous prime is 1661117. The next prime is 1661137. The reversal of 1661123 is 3211661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1661123 - 2⁶ = 1661059 is a prime.

It is a super-2 number, since 2×1661123² = 5518659242258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1661095 and 1661104.

It is not a weakly prime, because it can be changed into another prime (1661173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830561 + 830562.

It is an arithmetic number, because the mean of its divisors is an integer number (830562).

2^1661123 is an apocalyptic number.

1661123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661123 is an equidigital number, since it uses as much as digits as its factorization.

1661123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 20.

The square root of 1661123 is about 1288.8456075108. The cubic root of 1661123 is about 118.4315092590.

Adding to 1661123 its reverse (3211661), we get a palindrome (4872784).

The spelling of 1661123 in words is "one million, six hundred sixty-one thousand, one hundred twenty-three".