11661309 has 24 divisors (see below), whose sum is σ = 18686304. Its totient is φ = 6948000.

The previous prime is 11661289. The next prime is 11661317. The reversal of 11661309 is 90316611.

11661309 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11661309 - 2¹¹ = 11659261 is a prime.

It is a super-2 number, since 2×11661309² = 271972255186962, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11661319) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5074 + ... + 7004.

It is an arithmetic number, because the mean of its divisors is an integer number (778596).

Almost surely, 2^11661309 is an apocalyptic number.

It is an amenable number.

11661309 is a deficient number, since it is larger than the sum of its proper divisors (7024995).

11661309 is a wasteful number, since it uses less digits than its factorization.

11661309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2009 (or 2006 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 11661309 is about 3414.8658831644. The cubic root of 11661309 is about 226.7683470659.

It can be divided in two parts, 116 and 61309, that added together give a triangular number (61425 = T₃₅₀).

The spelling of 11661309 in words is "eleven million, six hundred sixty-one thousand, three hundred nine".