11671661 has 4 divisors (see below), whose sum is σ = 11787324. Its totient is φ = 11556000.

The previous prime is 11671637. The next prime is 11671663. The reversal of 11671661 is 16617611.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16617611 = 503 ⋅33037.

It can be written as a sum of positive squares in 2 ways, for example, as 5669161 + 6002500 = 2381^2 + 2450^2 .

It is a cyclic number.

It is not a de Polignac number, because 11671661 - 2¹⁴ = 11655277 is a prime.

It is a super-3 number, since 3×11671661³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11671663) 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 in 3 ways as a sum of consecutive naturals, for example, 57680 + ... + 57881.

It is an arithmetic number, because the mean of its divisors is an integer number (2946831).

Almost surely, 2^11671661 is an apocalyptic number.

It is an amenable number.

11671661 is a deficient number, since it is larger than the sum of its proper divisors (115663).

11671661 is a wasteful number, since it uses less digits than its factorization.

11671661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115662.

The product of its digits is 1512, while the sum is 29.

The square root of 11671661 is about 3416.3812726334. The cubic root of 11671661 is about 226.8354296329.

The spelling of 11671661 in words is "eleven million, six hundred seventy-one thousand, six hundred sixty-one".