1111661 has 2 divisors, whose sum is σ = 1111662. Its totient is φ = 1111660.

The previous prime is 1111651. The next prime is 1111667. The reversal of 1111661 is 1661111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 855625 + 256036 = 925^2 + 506^2 .

It is an emirp because it is prime and its reverse (1661111) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1111661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1111667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555830 + 555831.

It is an arithmetic number, because the mean of its divisors is an integer number (555831).

2^1111661 is an apocalyptic number.

It is an amenable number.

1111661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111661 is an equidigital number, since it uses as much as digits as its factorization.

1111661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36, while the sum is 17.

The square root of 1111661 is about 1054.3533563279. The cubic root of 1111661 is about 103.5915003735.

Adding to 1111661 its reverse (1661111), we get a palindrome (2772772).

It can be divided in two parts, 11 and 11661, that multiplied together give a triangular number (128271 = T₅₀₆).

The spelling of 1111661 in words is "one million, one hundred eleven thousand, six hundred sixty-one".